Current I bond rate
The current I bond rate is 5.51% for bonds issued November 2026 through April 2027: a fixed rate of 1.40% that lasts for the life of the bond, and a semiannual inflation rate of 2.04% that changes every six months.[1]
Worked: 0.0140 + 2 × 0.0204 + 0.0140 × 0.0204 = 0.055086, rounded to 5.51%. The previous rate, for bonds issued from May 2026, was 4.26%. The inflation part follows the consumer price index (CPI-U); prices rose 3.7% in the 12 months to September 2026.[5]
How I bond interest works
- Your rate changes every six months from your issue month, using the inflation rate announced most recently before each six-month period starts; the fixed part never changes.[2]
- Interest is added monthly and compounds semiannually. TreasuryDirect values bonds on a $25 basis, which this calculator copies.[3]
- You cannot cash the bond for 12 months. Before five years you lose the last three months of interest.
- The composite rate never goes below zero, even when the inflation part is negative.
- Limits: up to $10,000 in electronic I bonds per person per calendar year; bonds earn interest for 30 years.
Example from the calculator: $10,000 bought in November 2022 locked a 0.40% fixed rate. As of November 2026 it is worth $11,668.00; cashed now, the three-month penalty of $108.00 leaves $11,560.00.
I bond rate history
Fixed and inflation rates announced each May 1 and November 1 since 2016:[1][4]
| Announced | Fixed rate | Semiannual inflation | Composite for new bonds |
|---|---|---|---|
| Nov 2026 | 1.40% | 2.04% | 5.51% |
| May 2026 | 0.90% | 1.67% | 4.26% |
| Nov 2025 | 0.90% | 1.56% | 4.03% |
| May 2025 | 1.10% | 1.43% | 3.98% |
| Nov 2024 | 1.20% | 0.95% | 3.11% |
| May 2024 | 1.30% | 1.48% | 4.28% |
| Nov 2023 | 1.30% | 1.97% | 5.27% |
| May 2023 | 0.90% | 1.69% | 4.30% |
| Nov 2022 | 0.40% | 3.24% | 6.89% |
| May 2022 | 0.00% | 4.81% | 9.62% |
| Nov 2021 | 0.00% | 3.56% | 7.12% |
| May 2021 | 0.00% | 1.77% | 3.54% |
| Nov 2020 | 0.00% | 0.84% | 1.68% |
| May 2020 | 0.00% | 0.53% | 1.06% |
| Nov 2019 | 0.20% | 1.01% | 2.22% |
| May 2019 | 0.50% | 0.70% | 1.90% |
| Nov 2018 | 0.50% | 1.16% | 2.83% |
| May 2018 | 0.30% | 1.11% | 2.52% |
| Nov 2017 | 0.10% | 1.24% | 2.58% |
| May 2017 | 0.00% | 0.98% | 1.96% |
| Nov 2016 | 0.00% | 1.38% | 2.76% |
| May 2016 | 0.10% | 0.08% | 0.26% |
The composite in the last column is what a newly bought bond earns for its first six months. Older bonds keep their own fixed rate and pick up each new inflation rate on their own schedule, which the calculator handles.
Taxes on I bonds
I bond interest is subject to federal income tax but exempt from state and local income tax. You can report it each year or defer it until you cash the bond or it stops earning interest, and it may be tax-free if used for qualified higher education expenses.[2][6]
I bonds vs Treasury billsA bill locks today's short-term rate (the latest 52-week bill paid 4.496%) with no lockup beyond its term; an I bond's rate adjusts with inflation but cannot be cashed for a year. Compare with the T-bill calculator.
For savings that stay fully liquid, see the high-yield savings calculator; to test how inflation erodes a fixed return, the compound interest calculator has an inflation setting.
Related calculators
- T-bill calculatorPrice, investment rate and the state-tax edge over a CD
- High yield savings account calculatorYour APY against the FDIC national average, in dollars
- Compound interest calculatorDeposits, any compounding, inflation, goal seek, chart and CSV
- Rule of 72 calculatorDoubling time, and how far off the shortcut is
Frequently asked questions
What is the current I bond rate?
5.51% for bonds issued November 2026 through April 2027: 1.40% fixed plus a 2.04% semiannual inflation rate.
How is the I bond composite rate calculated?
Composite = fixed + 2 × semiannual inflation + fixed × semiannual inflation, rounded to two decimals and never below zero.
What happens if I cash an I bond before 5 years?
You lose the last three months of interest. You cannot cash it at all during the first 12 months.
How much is my I bond worth?
Enter the issue month and amount above. The calculator applies each six-month rate your bond has earned and shows the value and the amount you would receive if you cashed it.
How much can I invest in I bonds?
Up to $10,000 in electronic I bonds per person per calendar year through TreasuryDirect.
Sources
- I bonds interest rates
- I bonds (I bonds at a glance)
- 31 CFR part 359, Offering of United States Savings Bonds, Series I (§§ 359.15, 359.19, 359.39)
- Series I Savings Bond Interest Rates Effective November 1, 2026 (rate chart)
- Consumer Price Index, September 2026 (news release)
- Using bonds for higher education