Verification results
Independent engine: 91,279 of 91,279 official unit values match exactly. Older EE backtest: 5,160 of 5,160 values across 120 issue months match exactly.
Official paper calculator samples: 53 of 53 match all tested fields. Values use integer cents; no tolerance is applied. Query dates and amount differences appear below.
Value files cover 1992-05–2026-11; dataset updated 2026-05-01.
| Issue period | Rule | Source / checked |
|---|---|---|
| EE from May 2005 | Fixed for the first 20 years; monthly growth; guarantee at 20; final maturity at 30 | TreasuryDirect · 2026-10-03 |
| EE May 1997–April 2005 | Variable rates; monthly growth; guarantee at 17 or 20 years | TreasuryDirect · 2026-10-03 |
| EE May 1995–April 1997 | Semiannual value growth; guarantee at 17; final maturity at 30 | TreasuryDirect · 2026-10-03 |
| EE January 1980–April 1995 | All have stopped earning; historical growth follows CFR 351.22 and published monthly values. Historical current-rate metadata and accounting values at ages 3–5 months are unavailable here. | TreasuryDirect · 2026-10-03 |
| I | Composite rate with zero floor; monthly growth; issue-month six-month cycles | TreasuryDirect · 2026-10-03 |
| Series E / Savings Notes | Published final values; E has the November 1965 boundary | TreasuryDirect · 2026-10-03 |
| HH / H | HH stops at 20 years; H June 1952–January 1957 at 29 years 8 months, then 30 years | TreasuryDirect · 2026-10-03 |
Official calculator comparison samples
| Series | Amount | Issued | As of | Official value | This site | Difference | Queried |
|---|---|---|---|---|---|---|---|
| EE | $50.00 | 2005-05 | 2006-04 | $25.58 | $25.58 | $0.00 | 2026-10-03 |
| EE | $100.00 | 2005-05 | 2006-05 | $51.32 | $51.32 | $0.00 | 2026-10-03 |
| EE | $1,000.00 | 2005-05 | 2010-04 | $587.60 | $587.60 | $0.00 | 2026-10-03 |
| EE | $10,000.00 | 2005-05 | 2010-05 | $5948.00 | $5,948.00 | $0.00 | 2026-10-03 |
| EE | $100.00 | 2005-05 | 2025-04 | $99.72 | $99.72 | $0.00 | 2026-10-03 |
| EE | $100.00 | 2005-05 | 2025-05 | $100.00 | $100.00 | $0.00 | 2026-10-03 |
| EE | $100.00 | 2005-05 | 2025-06 | $100.28 | $100.28 | $0.00 | 2026-10-03 |
| EE | $100.00 | 2005-05 | 2026-10 | $105.08 | $105.08 | $0.00 | 2026-10-03 |
| EE | $50.00 | 2005-11 | 2026-10 | $51.48 | $51.48 | $0.00 | 2026-10-03 |
| EE | $75.00 | 2006-03 | 2026-10 | $76.41 | $76.41 | $0.00 | 2026-10-03 |
| EE | $500.00 | 2007-01 | 2026-10 | $505.80 | $505.80 | $0.00 | 2026-10-03 |
| EE | $1,000.00 | 2011-12 | 2026-10 | $547.60 | $547.60 | $0.00 | 2026-10-03 |
| EE | $50.00 | 1997-05 | 2026-10 | $64.74 | $64.74 | $0.00 | 2026-10-03 |
| EE | $75.00 | 1999-03 | 2026-10 | $93.90 | $93.90 | $0.00 | 2026-10-03 |
| EE | $100.00 | 2000-01 | 2026-10 | $124.28 | $124.28 | $0.00 | 2026-10-03 |
| EE | $200.00 | 2002-06 | 2026-10 | $238.40 | $238.40 | $0.00 | 2026-10-03 |
| EE | $100.00 | 2003-05 | 2020-04 | $72.36 | $72.36 | $0.00 | 2026-10-03 |
| EE | $100.00 | 2003-05 | 2020-05 | $100.00 | $100.00 | $0.00 | 2026-10-03 |
| EE | $100.00 | 2003-06 | 2023-05 | $74.96 | $74.96 | $0.00 | 2026-10-03 |
| EE | $100.00 | 2003-06 | 2023-06 | $100.00 | $100.00 | $0.00 | 2026-10-03 |
| EE | $50.00 | 1995-05 | 2025-04 | $60.74 | $60.74 | $0.00 | 2026-10-03 |
| EE | $100.00 | 1995-05 | 2025-05 | $123.56 | $123.56 | $0.00 | 2026-10-03 |
| EE | $500.00 | 1996-06 | 2026-10 | $634.80 | $634.80 | $0.00 | 2026-10-03 |
| EE | $1,000.00 | 1997-04 | 2026-10 | $1266.00 | $1,266.00 | $0.00 | 2026-10-03 |
| EE | $50.00 | 1980-01 | 2026-10 | $165.74 | $165.74 | $0.00 | 2026-10-03 |
| EE | $100.00 | 1987-06 | 2026-10 | $207.36 | $207.36 | $0.00 | 2026-10-03 |
| EE | $1,000.00 | 1993-02 | 2026-10 | $2073.60 | $2,073.60 | $0.00 | 2026-10-03 |
| EE | $10,000.00 | 1995-04 | 2026-10 | $16412.00 | $16,412.00 | $0.00 | 2026-10-03 |
| I | $50.00 | 1998-09 | 2026-10 | $263.24 | $263.24 | $0.00 | 2026-10-03 |
| I | $100.00 | 1998-11 | 2026-10 | $513.00 | $513.00 | $0.00 | 2026-10-03 |
| I | $100.00 | 1999-01 | 2026-10 | $507.40 | $507.40 | $0.00 | 2026-10-03 |
| I | $500.00 | 2000-05 | 2026-10 | $2544.00 | $2,544.00 | $0.00 | 2026-10-03 |
| I | $50.00 | 2002-03 | 2023-05 | $128.00 | $128.00 | $0.00 | 2026-10-03 |
| I | $100.00 | 2002-03 | 2023-05 | $256.00 | $256.00 | $0.00 | 2026-10-03 |
| I | $1,000.00 | 2003-01 | 2003-06 | $1006.80 | $1,006.80 | $0.00 | 2026-10-03 |
| I | $1,000.00 | 2003-01 | 2003-07 | $1010.00 | $1,010.00 | $0.00 | 2026-10-03 |
| I | $1,000.00 | 2003-02 | 2004-01 | $1029.20 | $1,029.20 | $0.00 | 2026-10-03 |
| I | $1,000.00 | 2003-02 | 2004-02 | $1033.60 | $1,033.60 | $0.00 | 2026-10-03 |
| I | $100.00 | 2008-05 | 2009-10 | $104.96 | $104.96 | $0.00 | 2026-10-03 |
| I | $100.00 | 2010-05 | 2015-04 | $110.76 | $110.76 | $0.00 | 2026-10-03 |
| I | $100.00 | 2010-05 | 2015-05 | $111.36 | $111.36 | $0.00 | 2026-10-03 |
| I | $1,000.00 | 2024-12 | 2025-11 | $1022.40 | $1,022.40 | $0.00 | 2026-10-03 |
| I | $1,000.00 | 2024-12 | 2025-12 | $1026.00 | $1,026.00 | $0.00 | 2026-10-03 |
| I | $100.00 | 2024-11 | 2026-10 | $106.68 | $106.68 | $0.00 | 2026-10-03 |
| E | $25.00 | 1941-05 | 2026-10 | $90.59 | $90.59 | $0.00 | 2026-10-03 |
| E | $100.00 | 1965-11 | 2026-10 | $736.12 | $736.12 | $0.00 | 2026-10-03 |
| E | $1,000.00 | 1965-12 | 2026-10 | $5124.80 | $5,124.80 | $0.00 | 2026-10-03 |
| E | $10,000.00 | 1980-06 | 2026-10 | $44700.00 | $44,700.00 | $0.00 | 2026-10-03 |
| SN | $25.00 | 1967-05 | 2026-10 | $153.33 | $153.33 | $0.00 | 2026-10-03 |
| SN | $100.00 | 1970-10 | 2026-10 | $554.80 | $554.80 | $0.00 | 2026-10-03 |
| I | $100.00 | 2021-11 | 2022-11 | $106.04 | $106.04 | $0.00 | 2026-10-03 |
| I | $100.00 | 2022-05 | 2023-05 | $106.48 | $106.48 | $0.00 | 2026-10-03 |
| EE | $100.00 | 1995-08 | 1996-01 | $50.00 | $50.00 | $0.00 | 2026-10-03 |
Disclosed legacy table conflicts
All 1,347,156 historical denomination records were checked. 1,346,841 match exactly; 315 Series E records disagree with the primary value files. Original conflicting rows remain intact. The current calculator uses the value files, including for those issue months. No new difference is accepted automatically.
Inspect all 315 conflicting records
| As of | Issue | Source line | Amount | Value-file result | Legacy result |
|---|---|---|---|---|---|
| 2007-12 | 1980-01 | 294 | $25.00 | $100.20 | $102.20 |
| 2007-12 | 1980-01 | 294 | $50.00 | $200.40 | $204.40 |
| 2007-12 | 1980-01 | 294 | $75.00 | $300.60 | $306.60 |
| 2007-12 | 1980-01 | 294 | $100.00 | $400.80 | $408.80 |
| 2007-12 | 1980-01 | 294 | $200.00 | $801.60 | $817.60 |
| 2007-12 | 1980-01 | 294 | $500.00 | $2,004.00 | $2,044.00 |
| 2007-12 | 1980-01 | 294 | $1,000.00 | $4,008.00 | $4,088.00 |
| 2007-12 | 1979-07 | 297 | $25.00 | $101.24 | $103.27 |
| 2007-12 | 1979-07 | 297 | $50.00 | $202.48 | $206.54 |
| 2007-12 | 1979-07 | 297 | $75.00 | $303.72 | $309.81 |
| 2007-12 | 1979-07 | 297 | $100.00 | $404.96 | $413.08 |
| 2007-12 | 1979-07 | 297 | $200.00 | $809.92 | $826.16 |
| 2007-12 | 1979-07 | 297 | $500.00 | $2,024.80 | $2,065.40 |
| 2007-12 | 1979-07 | 297 | $1,000.00 | $4,049.60 | $4,130.80 |
| 2007-12 | 1979-01 | 300 | $25.00 | $102.04 | $104.08 |
| 2007-12 | 1979-01 | 300 | $50.00 | $204.08 | $208.16 |
| 2007-12 | 1979-01 | 300 | $75.00 | $306.12 | $312.24 |
| 2007-12 | 1979-01 | 300 | $100.00 | $408.16 | $416.32 |
| 2007-12 | 1979-01 | 300 | $200.00 | $816.32 | $832.64 |
| 2007-12 | 1979-01 | 300 | $500.00 | $2,040.80 | $2,081.60 |
| 2007-12 | 1979-01 | 300 | $1,000.00 | $4,081.60 | $4,163.20 |
| 2007-12 | 1978-07 | 304 | $25.00 | $102.81 | $104.87 |
| 2007-12 | 1978-07 | 304 | $50.00 | $205.62 | $209.74 |
| 2007-12 | 1978-07 | 304 | $75.00 | $308.43 | $314.61 |
| 2007-12 | 1978-07 | 304 | $100.00 | $411.24 | $419.48 |
| 2007-12 | 1978-07 | 304 | $200.00 | $822.48 | $838.96 |
| 2007-12 | 1978-07 | 304 | $500.00 | $2,056.20 | $2,097.40 |
| 2007-12 | 1978-07 | 304 | $1,000.00 | $4,112.40 | $4,194.80 |
| 2007-12 | 1978-01 | 309 | $25.00 | $125.93 | $128.45 |
| 2007-12 | 1978-01 | 309 | $50.00 | $251.86 | $256.90 |
| 2007-12 | 1978-01 | 309 | $75.00 | $377.79 | $385.35 |
| 2007-12 | 1978-01 | 309 | $100.00 | $503.72 | $513.80 |
| 2007-12 | 1978-01 | 309 | $200.00 | $1,007.44 | $1,027.60 |
| 2007-12 | 1978-01 | 309 | $500.00 | $2,518.60 | $2,569.00 |
| 2007-12 | 1978-01 | 309 | $1,000.00 | $5,037.20 | $5,138.00 |
| 2007-12 | 1980-01 | 318 | $25.00 | $100.20 | $102.20 |
| 2007-12 | 1980-01 | 318 | $50.00 | $200.40 | $204.40 |
| 2007-12 | 1980-01 | 318 | $75.00 | $300.60 | $306.60 |
| 2007-12 | 1980-01 | 318 | $100.00 | $400.80 | $408.80 |
| 2007-12 | 1980-01 | 318 | $200.00 | $801.60 | $817.60 |
| 2007-12 | 1980-01 | 318 | $500.00 | $2,004.00 | $2,044.00 |
| 2007-12 | 1980-01 | 318 | $1,000.00 | $4,008.00 | $4,088.00 |
| 2007-12 | 1980-02 | 318 | $25.00 | $100.20 | $102.20 |
| 2007-12 | 1980-02 | 318 | $50.00 | $200.40 | $204.40 |
| 2007-12 | 1980-02 | 318 | $75.00 | $300.60 | $306.60 |
| 2007-12 | 1980-02 | 318 | $100.00 | $400.80 | $408.80 |
| 2007-12 | 1980-02 | 318 | $200.00 | $801.60 | $817.60 |
| 2007-12 | 1980-02 | 318 | $500.00 | $2,004.00 | $2,044.00 |
| 2007-12 | 1980-02 | 318 | $1,000.00 | $4,008.00 | $4,088.00 |
| 2007-12 | 1979-07 | 321 | $25.00 | $101.24 | $103.27 |
| 2007-12 | 1979-07 | 321 | $50.00 | $202.48 | $206.54 |
| 2007-12 | 1979-07 | 321 | $75.00 | $303.72 | $309.81 |
| 2007-12 | 1979-07 | 321 | $100.00 | $404.96 | $413.08 |
| 2007-12 | 1979-07 | 321 | $200.00 | $809.92 | $826.16 |
| 2007-12 | 1979-07 | 321 | $500.00 | $2,024.80 | $2,065.40 |
| 2007-12 | 1979-07 | 321 | $1,000.00 | $4,049.60 | $4,130.80 |
| 2007-12 | 1979-08 | 321 | $25.00 | $101.24 | $103.27 |
| 2007-12 | 1979-08 | 321 | $50.00 | $202.48 | $206.54 |
| 2007-12 | 1979-08 | 321 | $75.00 | $303.72 | $309.81 |
| 2007-12 | 1979-08 | 321 | $100.00 | $404.96 | $413.08 |
| 2007-12 | 1979-08 | 321 | $200.00 | $809.92 | $826.16 |
| 2007-12 | 1979-08 | 321 | $500.00 | $2,024.80 | $2,065.40 |
| 2007-12 | 1979-08 | 321 | $1,000.00 | $4,049.60 | $4,130.80 |
| 2007-12 | 1979-01 | 324 | $25.00 | $102.04 | $104.08 |
| 2007-12 | 1979-01 | 324 | $50.00 | $204.08 | $208.16 |
| 2007-12 | 1979-01 | 324 | $75.00 | $306.12 | $312.24 |
| 2007-12 | 1979-01 | 324 | $100.00 | $408.16 | $416.32 |
| 2007-12 | 1979-01 | 324 | $200.00 | $816.32 | $832.64 |
| 2007-12 | 1979-01 | 324 | $500.00 | $2,040.80 | $2,081.60 |
| 2007-12 | 1979-01 | 324 | $1,000.00 | $4,081.60 | $4,163.20 |
| 2007-12 | 1979-02 | 324 | $25.00 | $102.04 | $104.08 |
| 2007-12 | 1979-02 | 324 | $50.00 | $204.08 | $208.16 |
| 2007-12 | 1979-02 | 324 | $75.00 | $306.12 | $312.24 |
| 2007-12 | 1979-02 | 324 | $100.00 | $408.16 | $416.32 |
| 2007-12 | 1979-02 | 324 | $200.00 | $816.32 | $832.64 |
| 2007-12 | 1979-02 | 324 | $500.00 | $2,040.80 | $2,081.60 |
| 2007-12 | 1979-02 | 324 | $1,000.00 | $4,081.60 | $4,163.20 |
| 2007-12 | 1978-07 | 328 | $25.00 | $102.81 | $104.87 |
| 2007-12 | 1978-07 | 328 | $50.00 | $205.62 | $209.74 |
| 2007-12 | 1978-07 | 328 | $75.00 | $308.43 | $314.61 |
| 2007-12 | 1978-07 | 328 | $100.00 | $411.24 | $419.48 |
| 2007-12 | 1978-07 | 328 | $200.00 | $822.48 | $838.96 |
| 2007-12 | 1978-07 | 328 | $500.00 | $2,056.20 | $2,097.40 |
| 2007-12 | 1978-07 | 328 | $1,000.00 | $4,112.40 | $4,194.80 |
| 2007-12 | 1978-08 | 328 | $25.00 | $102.81 | $104.87 |
| 2007-12 | 1978-08 | 328 | $50.00 | $205.62 | $209.74 |
| 2007-12 | 1978-08 | 328 | $75.00 | $308.43 | $314.61 |
| 2007-12 | 1978-08 | 328 | $100.00 | $411.24 | $419.48 |
| 2007-12 | 1978-08 | 328 | $200.00 | $822.48 | $838.96 |
| 2007-12 | 1978-08 | 328 | $500.00 | $2,056.20 | $2,097.40 |
| 2007-12 | 1978-08 | 328 | $1,000.00 | $4,112.40 | $4,194.80 |
| 2007-12 | 1978-01 | 332 | $25.00 | $125.93 | $128.45 |
| 2007-12 | 1978-01 | 332 | $50.00 | $251.86 | $256.90 |
| 2007-12 | 1978-01 | 332 | $75.00 | $377.79 | $385.35 |
| 2007-12 | 1978-01 | 332 | $100.00 | $503.72 | $513.80 |
| 2007-12 | 1978-01 | 332 | $200.00 | $1,007.44 | $1,027.60 |
| 2007-12 | 1978-01 | 332 | $500.00 | $2,518.60 | $2,569.00 |
| 2007-12 | 1978-01 | 332 | $1,000.00 | $5,037.20 | $5,138.00 |
| 2007-12 | 1978-02 | 332 | $25.00 | $125.93 | $128.45 |
| 2007-12 | 1978-02 | 332 | $50.00 | $251.86 | $256.90 |
| 2007-12 | 1978-02 | 332 | $75.00 | $377.79 | $385.35 |
| 2007-12 | 1978-02 | 332 | $100.00 | $503.72 | $513.80 |
| 2007-12 | 1978-02 | 332 | $200.00 | $1,007.44 | $1,027.60 |
| 2007-12 | 1978-02 | 332 | $500.00 | $2,518.60 | $2,569.00 |
| 2007-12 | 1978-02 | 332 | $1,000.00 | $5,037.20 | $5,138.00 |
| 2008-01 | 1980-02 | 296 | $25.00 | $100.20 | $102.20 |
| 2008-01 | 1980-02 | 296 | $50.00 | $200.40 | $204.40 |
| 2008-01 | 1980-02 | 296 | $75.00 | $300.60 | $306.60 |
| 2008-01 | 1980-02 | 296 | $100.00 | $400.80 | $408.80 |
| 2008-01 | 1980-02 | 296 | $200.00 | $801.60 | $817.60 |
| 2008-01 | 1980-02 | 296 | $500.00 | $2,004.00 | $2,044.00 |
| 2008-01 | 1980-02 | 296 | $1,000.00 | $4,008.00 | $4,088.00 |
| 2008-01 | 1980-03 | 296 | $25.00 | $100.20 | $102.20 |
| 2008-01 | 1980-03 | 296 | $50.00 | $200.40 | $204.40 |
| 2008-01 | 1980-03 | 296 | $75.00 | $300.60 | $306.60 |
| 2008-01 | 1980-03 | 296 | $100.00 | $400.80 | $408.80 |
| 2008-01 | 1980-03 | 296 | $200.00 | $801.60 | $817.60 |
| 2008-01 | 1980-03 | 296 | $500.00 | $2,004.00 | $2,044.00 |
| 2008-01 | 1980-03 | 296 | $1,000.00 | $4,008.00 | $4,088.00 |
| 2008-01 | 1979-08 | 299 | $25.00 | $101.24 | $103.27 |
| 2008-01 | 1979-08 | 299 | $50.00 | $202.48 | $206.54 |
| 2008-01 | 1979-08 | 299 | $75.00 | $303.72 | $309.81 |
| 2008-01 | 1979-08 | 299 | $100.00 | $404.96 | $413.08 |
| 2008-01 | 1979-08 | 299 | $200.00 | $809.92 | $826.16 |
| 2008-01 | 1979-08 | 299 | $500.00 | $2,024.80 | $2,065.40 |
| 2008-01 | 1979-08 | 299 | $1,000.00 | $4,049.60 | $4,130.80 |
| 2008-01 | 1979-09 | 299 | $25.00 | $101.24 | $103.27 |
| 2008-01 | 1979-09 | 299 | $50.00 | $202.48 | $206.54 |
| 2008-01 | 1979-09 | 299 | $75.00 | $303.72 | $309.81 |
| 2008-01 | 1979-09 | 299 | $100.00 | $404.96 | $413.08 |
| 2008-01 | 1979-09 | 299 | $200.00 | $809.92 | $826.16 |
| 2008-01 | 1979-09 | 299 | $500.00 | $2,024.80 | $2,065.40 |
| 2008-01 | 1979-09 | 299 | $1,000.00 | $4,049.60 | $4,130.80 |
| 2008-01 | 1979-02 | 302 | $25.00 | $102.04 | $104.08 |
| 2008-01 | 1979-02 | 302 | $50.00 | $204.08 | $208.16 |
| 2008-01 | 1979-02 | 302 | $75.00 | $306.12 | $312.24 |
| 2008-01 | 1979-02 | 302 | $100.00 | $408.16 | $416.32 |
| 2008-01 | 1979-02 | 302 | $200.00 | $816.32 | $832.64 |
| 2008-01 | 1979-02 | 302 | $500.00 | $2,040.80 | $2,081.60 |
| 2008-01 | 1979-02 | 302 | $1,000.00 | $4,081.60 | $4,163.20 |
| 2008-01 | 1979-03 | 302 | $25.00 | $102.04 | $104.08 |
| 2008-01 | 1979-03 | 302 | $50.00 | $204.08 | $208.16 |
| 2008-01 | 1979-03 | 302 | $75.00 | $306.12 | $312.24 |
| 2008-01 | 1979-03 | 302 | $100.00 | $408.16 | $416.32 |
| 2008-01 | 1979-03 | 302 | $200.00 | $816.32 | $832.64 |
| 2008-01 | 1979-03 | 302 | $500.00 | $2,040.80 | $2,081.60 |
| 2008-01 | 1979-03 | 302 | $1,000.00 | $4,081.60 | $4,163.20 |
| 2008-01 | 1978-08 | 306 | $25.00 | $102.81 | $104.87 |
| 2008-01 | 1978-08 | 306 | $50.00 | $205.62 | $209.74 |
| 2008-01 | 1978-08 | 306 | $75.00 | $308.43 | $314.61 |
| 2008-01 | 1978-08 | 306 | $100.00 | $411.24 | $419.48 |
| 2008-01 | 1978-08 | 306 | $200.00 | $822.48 | $838.96 |
| 2008-01 | 1978-08 | 306 | $500.00 | $2,056.20 | $2,097.40 |
| 2008-01 | 1978-08 | 306 | $1,000.00 | $4,112.40 | $4,194.80 |
| 2008-01 | 1978-09 | 306 | $25.00 | $102.81 | $104.87 |
| 2008-01 | 1978-09 | 306 | $50.00 | $205.62 | $209.74 |
| 2008-01 | 1978-09 | 306 | $75.00 | $308.43 | $314.61 |
| 2008-01 | 1978-09 | 306 | $100.00 | $411.24 | $419.48 |
| 2008-01 | 1978-09 | 306 | $200.00 | $822.48 | $838.96 |
| 2008-01 | 1978-09 | 306 | $500.00 | $2,056.20 | $2,097.40 |
| 2008-01 | 1978-09 | 306 | $1,000.00 | $4,112.40 | $4,194.80 |
| 2008-01 | 1978-03 | 310 | $25.00 | $106.27 | $108.54 |
| 2008-01 | 1978-03 | 310 | $50.00 | $212.54 | $217.08 |
| 2008-01 | 1978-03 | 310 | $75.00 | $318.81 | $325.62 |
| 2008-01 | 1978-03 | 310 | $100.00 | $425.08 | $434.16 |
| 2008-01 | 1978-03 | 310 | $200.00 | $850.16 | $868.32 |
| 2008-01 | 1978-03 | 310 | $500.00 | $2,125.40 | $2,170.80 |
| 2008-01 | 1978-03 | 310 | $1,000.00 | $4,250.80 | $4,341.60 |
| 2008-01 | 1978-02 | 311 | $25.00 | $125.93 | $128.45 |
| 2008-01 | 1978-02 | 311 | $50.00 | $251.86 | $256.90 |
| 2008-01 | 1978-02 | 311 | $75.00 | $377.79 | $385.35 |
| 2008-01 | 1978-02 | 311 | $100.00 | $503.72 | $513.80 |
| 2008-01 | 1978-02 | 311 | $200.00 | $1,007.44 | $1,027.60 |
| 2008-01 | 1978-02 | 311 | $500.00 | $2,518.60 | $2,569.00 |
| 2008-01 | 1978-02 | 311 | $1,000.00 | $5,037.20 | $5,138.00 |
| 2008-02 | 1980-03 | 295 | $25.00 | $100.20 | $102.20 |
| 2008-02 | 1980-03 | 295 | $50.00 | $200.40 | $204.40 |
| 2008-02 | 1980-03 | 295 | $75.00 | $300.60 | $306.60 |
| 2008-02 | 1980-03 | 295 | $100.00 | $400.80 | $408.80 |
| 2008-02 | 1980-03 | 295 | $200.00 | $801.60 | $817.60 |
| 2008-02 | 1980-03 | 295 | $500.00 | $2,004.00 | $2,044.00 |
| 2008-02 | 1980-03 | 295 | $1,000.00 | $4,008.00 | $4,088.00 |
| 2008-02 | 1980-04 | 295 | $25.00 | $100.20 | $102.20 |
| 2008-02 | 1980-04 | 295 | $50.00 | $200.40 | $204.40 |
| 2008-02 | 1980-04 | 295 | $75.00 | $300.60 | $306.60 |
| 2008-02 | 1980-04 | 295 | $100.00 | $400.80 | $408.80 |
| 2008-02 | 1980-04 | 295 | $200.00 | $801.60 | $817.60 |
| 2008-02 | 1980-04 | 295 | $500.00 | $2,004.00 | $2,044.00 |
| 2008-02 | 1980-04 | 295 | $1,000.00 | $4,008.00 | $4,088.00 |
| 2008-02 | 1979-09 | 297 | $25.00 | $101.24 | $103.27 |
| 2008-02 | 1979-09 | 297 | $50.00 | $202.48 | $206.54 |
| 2008-02 | 1979-09 | 297 | $75.00 | $303.72 | $309.81 |
| 2008-02 | 1979-09 | 297 | $100.00 | $404.96 | $413.08 |
| 2008-02 | 1979-09 | 297 | $200.00 | $809.92 | $826.16 |
| 2008-02 | 1979-09 | 297 | $500.00 | $2,024.80 | $2,065.40 |
| 2008-02 | 1979-09 | 297 | $1,000.00 | $4,049.60 | $4,130.80 |
| 2008-02 | 1979-10 | 297 | $25.00 | $101.24 | $103.27 |
| 2008-02 | 1979-10 | 297 | $50.00 | $202.48 | $206.54 |
| 2008-02 | 1979-10 | 297 | $75.00 | $303.72 | $309.81 |
| 2008-02 | 1979-10 | 297 | $100.00 | $404.96 | $413.08 |
| 2008-02 | 1979-10 | 297 | $200.00 | $809.92 | $826.16 |
| 2008-02 | 1979-10 | 297 | $500.00 | $2,024.80 | $2,065.40 |
| 2008-02 | 1979-10 | 297 | $1,000.00 | $4,049.60 | $4,130.80 |
| 2008-02 | 1979-03 | 299 | $25.00 | $102.04 | $104.08 |
| 2008-02 | 1979-03 | 299 | $50.00 | $204.08 | $208.16 |
| 2008-02 | 1979-03 | 299 | $75.00 | $306.12 | $312.24 |
| 2008-02 | 1979-03 | 299 | $100.00 | $408.16 | $416.32 |
| 2008-02 | 1979-03 | 299 | $200.00 | $816.32 | $832.64 |
| 2008-02 | 1979-03 | 299 | $500.00 | $2,040.80 | $2,081.60 |
| 2008-02 | 1979-03 | 299 | $1,000.00 | $4,081.60 | $4,163.20 |
| 2008-02 | 1979-04 | 299 | $25.00 | $102.04 | $104.08 |
| 2008-02 | 1979-04 | 299 | $50.00 | $204.08 | $208.16 |
| 2008-02 | 1979-04 | 299 | $75.00 | $306.12 | $312.24 |
| 2008-02 | 1979-04 | 299 | $100.00 | $408.16 | $416.32 |
| 2008-02 | 1979-04 | 299 | $200.00 | $816.32 | $832.64 |
| 2008-02 | 1979-04 | 299 | $500.00 | $2,040.80 | $2,081.60 |
| 2008-02 | 1979-04 | 299 | $1,000.00 | $4,081.60 | $4,163.20 |
| 2008-02 | 1978-09 | 302 | $25.00 | $102.81 | $104.87 |
| 2008-02 | 1978-09 | 302 | $50.00 | $205.62 | $209.74 |
| 2008-02 | 1978-09 | 302 | $75.00 | $308.43 | $314.61 |
| 2008-02 | 1978-09 | 302 | $100.00 | $411.24 | $419.48 |
| 2008-02 | 1978-09 | 302 | $200.00 | $822.48 | $838.96 |
| 2008-02 | 1978-09 | 302 | $500.00 | $2,056.20 | $2,097.40 |
| 2008-02 | 1978-09 | 302 | $1,000.00 | $4,112.40 | $4,194.80 |
| 2008-02 | 1978-10 | 302 | $25.00 | $102.81 | $104.87 |
| 2008-02 | 1978-10 | 302 | $50.00 | $205.62 | $209.74 |
| 2008-02 | 1978-10 | 302 | $75.00 | $308.43 | $314.61 |
| 2008-02 | 1978-10 | 302 | $100.00 | $411.24 | $419.48 |
| 2008-02 | 1978-10 | 302 | $200.00 | $822.48 | $838.96 |
| 2008-02 | 1978-10 | 302 | $500.00 | $2,056.20 | $2,097.40 |
| 2008-02 | 1978-10 | 302 | $1,000.00 | $4,112.40 | $4,194.80 |
| 2008-02 | 1978-03 | 305 | $25.00 | $106.27 | $108.54 |
| 2008-02 | 1978-03 | 305 | $50.00 | $212.54 | $217.08 |
| 2008-02 | 1978-03 | 305 | $75.00 | $318.81 | $325.62 |
| 2008-02 | 1978-03 | 305 | $100.00 | $425.08 | $434.16 |
| 2008-02 | 1978-03 | 305 | $200.00 | $850.16 | $868.32 |
| 2008-02 | 1978-03 | 305 | $500.00 | $2,125.40 | $2,170.80 |
| 2008-02 | 1978-03 | 305 | $1,000.00 | $4,250.80 | $4,341.60 |
| 2008-02 | 1978-04 | 305 | $25.00 | $106.27 | $108.54 |
| 2008-02 | 1978-04 | 305 | $50.00 | $212.54 | $217.08 |
| 2008-02 | 1978-04 | 305 | $75.00 | $318.81 | $325.62 |
| 2008-02 | 1978-04 | 305 | $100.00 | $425.08 | $434.16 |
| 2008-02 | 1978-04 | 305 | $200.00 | $850.16 | $868.32 |
| 2008-02 | 1978-04 | 305 | $500.00 | $2,125.40 | $2,170.80 |
| 2008-02 | 1978-04 | 305 | $1,000.00 | $4,250.80 | $4,341.60 |
| 2008-03 | 1980-05 | 299 | $25.00 | $101.21 | $103.24 |
| 2008-03 | 1980-05 | 299 | $50.00 | $202.42 | $206.48 |
| 2008-03 | 1980-05 | 299 | $75.00 | $303.63 | $309.72 |
| 2008-03 | 1980-05 | 299 | $100.00 | $404.84 | $412.96 |
| 2008-03 | 1980-05 | 299 | $200.00 | $809.68 | $825.92 |
| 2008-03 | 1980-05 | 299 | $500.00 | $2,024.20 | $2,064.80 |
| 2008-03 | 1980-05 | 299 | $1,000.00 | $4,048.40 | $4,129.60 |
| 2008-03 | 1980-04 | 300 | $25.00 | $100.20 | $102.20 |
| 2008-03 | 1980-04 | 300 | $50.00 | $200.40 | $204.40 |
| 2008-03 | 1980-04 | 300 | $75.00 | $300.60 | $306.60 |
| 2008-03 | 1980-04 | 300 | $100.00 | $400.80 | $408.80 |
| 2008-03 | 1980-04 | 300 | $200.00 | $801.60 | $817.60 |
| 2008-03 | 1980-04 | 300 | $500.00 | $2,004.00 | $2,044.00 |
| 2008-03 | 1980-04 | 300 | $1,000.00 | $4,008.00 | $4,088.00 |
| 2008-03 | 1979-11 | 302 | $25.00 | $102.20 | $104.24 |
| 2008-03 | 1979-11 | 302 | $50.00 | $204.40 | $208.48 |
| 2008-03 | 1979-11 | 302 | $75.00 | $306.60 | $312.72 |
| 2008-03 | 1979-11 | 302 | $100.00 | $408.80 | $416.96 |
| 2008-03 | 1979-11 | 302 | $200.00 | $817.60 | $833.92 |
| 2008-03 | 1979-11 | 302 | $500.00 | $2,044.00 | $2,084.80 |
| 2008-03 | 1979-11 | 302 | $1,000.00 | $4,088.00 | $4,169.60 |
| 2008-03 | 1979-10 | 303 | $25.00 | $101.24 | $103.27 |
| 2008-03 | 1979-10 | 303 | $50.00 | $202.48 | $206.54 |
| 2008-03 | 1979-10 | 303 | $75.00 | $303.72 | $309.81 |
| 2008-03 | 1979-10 | 303 | $100.00 | $404.96 | $413.08 |
| 2008-03 | 1979-10 | 303 | $200.00 | $809.92 | $826.16 |
| 2008-03 | 1979-10 | 303 | $500.00 | $2,024.80 | $2,065.40 |
| 2008-03 | 1979-10 | 303 | $1,000.00 | $4,049.60 | $4,130.80 |
| 2008-03 | 1979-05 | 304 | $25.00 | $103.03 | $105.09 |
| 2008-03 | 1979-05 | 304 | $50.00 | $206.06 | $210.18 |
| 2008-03 | 1979-05 | 304 | $75.00 | $309.09 | $315.27 |
| 2008-03 | 1979-05 | 304 | $100.00 | $412.12 | $420.36 |
| 2008-03 | 1979-05 | 304 | $200.00 | $824.24 | $840.72 |
| 2008-03 | 1979-05 | 304 | $500.00 | $2,060.60 | $2,101.80 |
| 2008-03 | 1979-05 | 304 | $1,000.00 | $4,121.20 | $4,203.60 |
| 2008-03 | 1979-04 | 305 | $25.00 | $102.04 | $104.08 |
| 2008-03 | 1979-04 | 305 | $50.00 | $204.08 | $208.16 |
| 2008-03 | 1979-04 | 305 | $75.00 | $306.12 | $312.24 |
| 2008-03 | 1979-04 | 305 | $100.00 | $408.16 | $416.32 |
| 2008-03 | 1979-04 | 305 | $200.00 | $816.32 | $832.64 |
| 2008-03 | 1979-04 | 305 | $500.00 | $2,040.80 | $2,081.60 |
| 2008-03 | 1979-04 | 305 | $1,000.00 | $4,081.60 | $4,163.20 |
| 2008-03 | 1978-11 | 307 | $25.00 | $103.79 | $105.86 |
| 2008-03 | 1978-11 | 307 | $50.00 | $207.58 | $211.72 |
| 2008-03 | 1978-11 | 307 | $75.00 | $311.37 | $317.58 |
| 2008-03 | 1978-11 | 307 | $100.00 | $415.16 | $423.44 |
| 2008-03 | 1978-11 | 307 | $200.00 | $830.32 | $846.88 |
| 2008-03 | 1978-11 | 307 | $500.00 | $2,075.80 | $2,117.20 |
| 2008-03 | 1978-11 | 307 | $1,000.00 | $4,151.60 | $4,234.40 |
| 2008-03 | 1978-10 | 308 | $25.00 | $102.81 | $104.87 |
| 2008-03 | 1978-10 | 308 | $50.00 | $205.62 | $209.74 |
| 2008-03 | 1978-10 | 308 | $75.00 | $308.43 | $314.61 |
| 2008-03 | 1978-10 | 308 | $100.00 | $411.24 | $419.48 |
| 2008-03 | 1978-10 | 308 | $200.00 | $822.48 | $838.96 |
| 2008-03 | 1978-10 | 308 | $500.00 | $2,056.20 | $2,097.40 |
| 2008-03 | 1978-10 | 308 | $1,000.00 | $4,112.40 | $4,194.80 |
| 2008-03 | 1978-05 | 310 | $25.00 | $104.58 | $106.67 |
| 2008-03 | 1978-05 | 310 | $50.00 | $209.16 | $213.34 |
| 2008-03 | 1978-05 | 310 | $75.00 | $313.74 | $320.01 |
| 2008-03 | 1978-05 | 310 | $100.00 | $418.32 | $426.68 |
| 2008-03 | 1978-05 | 310 | $200.00 | $836.64 | $853.36 |
| 2008-03 | 1978-05 | 310 | $500.00 | $2,091.60 | $2,133.40 |
| 2008-03 | 1978-05 | 310 | $1,000.00 | $4,183.20 | $4,266.80 |
| 2008-03 | 1978-04 | 311 | $25.00 | $106.27 | $108.54 |
| 2008-03 | 1978-04 | 311 | $50.00 | $212.54 | $217.08 |
| 2008-03 | 1978-04 | 311 | $75.00 | $318.81 | $325.62 |
| 2008-03 | 1978-04 | 311 | $100.00 | $425.08 | $434.16 |
| 2008-03 | 1978-04 | 311 | $200.00 | $850.16 | $868.32 |
| 2008-03 | 1978-04 | 311 | $500.00 | $2,125.40 | $2,170.80 |
| 2008-03 | 1978-04 | 311 | $1,000.00 | $4,250.80 | $4,341.60 |
Update log
2026-10-03: collected official value files and rate histories, implemented integer-cent calculations, recorded paper calculator samples and disclosed archived Series E conflicts. Current rate records cover the May 2026 announcement window. No November 2026 rate has been assumed.
The engine and tests are prepared for a public source repository; that repository has not been published yet.
Data sources
The primary source is Treasury Fiscal Data’s Savings Bonds Value Files through the sb_value API. Each cell is a $25 value selected by series, issue date and valuation month. Null means no issue in that cell; zero identifies a holding inside its minimum holding period.
The archived redemption tables ended in May 2023. They verify paper scaling and are not the source of current values. Original conflicting records are retained and disclosed below.
Calculation rules
Monthly interest follows the fractional-power formula in 31 CFR Part 359. The engine rounds the $25 unit to an integer cent and compounds at six-month boundaries. Integer sixth-power comparisons resolve the half-cent boundary without floating-point dollar arithmetic.
The EE paper unit starts at $12.50; I starts at $25. Early redemption reduces the earning period by three months before five years. The EE guarantee applies at original maturity. Earlier active EE issues use semiannual anchors, and each approved issue month must pass historical backtesting.
Paper denominations scale from the rounded unit. Electronic I follows 31 CFR 359.55; electronic EE follows 31 CFR 351.70, using invested principal. Proportional results round to the nearest cent. Official calculator samples validate paper values and do not directly validate electronic account balances.
Known limits
Treasury may change EE extension terms after the first 20 years. File-covered values are authoritative. Calculations beyond published files use documented rates, are labeled as estimates and require official confirmation. Unsupported historical fallback periods keep the last official value and its date.
The site does not calculate taxes, process payments, confirm ownership or provide investment advice. “Report an error” prepares the selected inputs in an email. Do not send serial numbers, account details or identifying documents. See Contact and About the independent operator.
Open the Savings Bond Calculator for a holding, the EE calculator for guarantees or the I rate history for announced components.
Content updated 2026-10-03. Information only; not financial or tax advice.