I Bond Calculator
What your Series I savings bonds are worth, the rate they earn now, and what cashing in early costs. New I bonds earn 4.26% until October 2026.
I bond rates for new bonds, by six-month period (Treasury)
| Bought | Fixed rate | Inflation (semiannual) | Rate for the first six months |
|---|---|---|---|
| May 2026 to October 2026 | 0.90% | 1.67% | 4.26% |
| November 2025 to April 2026 | 0.90% | 1.56% | 4.03% |
| May 2025 to October 2025 | 1.10% | 1.43% | 3.98% |
| November 2024 to April 2025 | 1.20% | 0.95% | 3.11% |
| May 2024 to October 2024 | 1.30% | 1.48% | 4.28% |
| November 2023 to April 2024 | 1.30% | 1.97% | 5.27% |
| May 2023 to October 2023 | 0.90% | 1.69% | 4.30% |
| November 2022 to April 2023 | 0.40% | 3.24% | 6.89% |
| May 2022 to October 2022 | 0.00% | 4.81% | 9.62% |
| November 2021 to April 2022 | 0.00% | 3.56% | 7.12% |
What $10,000 of I bonds bought in January of past years is worth in January 1970
| Bought | Fixed rate | Worth now | Interest |
|---|---|---|---|
| January 2001 | 3.40% | $10,000 | $0 |
| January 2008 | 1.20% | $10,000 | $0 |
| January 2016 | 0.10% | $10,000 | $0 |
| January 2020 | 0.20% | $10,000 | $0 |
| January 2021 | 0.00% | $10,000 | $0 |
| January 2022 | 0.00% | $10,000 | $0 |
| January 2023 | 0.40% | $10,000 | $0 |
| January 2024 | 1.30% | $10,000 | $0 |
How this calculator works
An I bond's rate has two parts: a fixed rate set when you buy it, which lasts for its 30-year life, and an inflation rate Treasury resets every May 1 and November 1 from the CPI. The rate for each six months is fixed + 2 × semiannual inflation + fixed × semiannual inflation, never below zero.
Each bond's rate changes every six months from the month you bought it, using the inflation rate announced most recently. Interest is added monthly and compounds every six months. Like Treasury, the calculator values a $25 bond, rounds to the cent, and scales to your amount.
Checked against Treasury: the rates reproduce all 9,690 published combined rates, and the values match Treasury's official redemption values to the cent.
What it assumes
- Projections assume today's inflation rate continues; the real rate will change every six months.
- Values are before tax. Interest is taxed federally when you cash in (or report it yearly if you choose), and is exempt from state and local income tax.
- This is for Series I bonds. Series EE bonds earn a fixed rate and are guaranteed to double in 20 years; TreasuryDirect's calculator values paper EE bonds.
Questions people ask
What is the I bond rate now?
4.26% for I bonds bought through October 2026: a 0.90% fixed rate plus 1.67% of semiannual inflation. Bonds you already own earn their own fixed rate plus the same inflation rate.
How much are my I bonds worth?
Enter the amount and the month you bought them above. The value includes interest to date; if they are under five years old, cashing in costs the last three months' interest.
When can I cash in I bonds?
After 12 months. Before five years you lose the last three months of interest; after five years there is no penalty. They stop earning after 30 years.
How much can I buy?
Up to $10,000 of electronic I bonds a calendar year per person through TreasuryDirect, plus up to $5,000 of paper I bonds with a federal tax refund.
Are I bonds taxed?
Federal income tax applies to the interest, usually when you cash in, but state and local income tax don't. Interest used for qualified higher education can be tax-free, subject to income limits.
I bonds or a high-yield savings account?
I bonds protect against inflation and avoid state tax, but lock money up for a year and charge a penalty for five. Savings accounts are liquid. The after-tax yield calculator compares yields once state tax is counted.
Terms explained
Related calculators
Sources
- Treasury Fiscal Data: I Bonds Interest Rates
- Treasury Fiscal Data: Savings Bonds Value Files
- TreasuryDirect: I bonds
Updated by the RateHerald team. The maths is tested against worked examples; report a problem.