I Bond calculator
The first six months earn today's rate. After that the inflation part resets every six months; this holds it steady.
| Held for | Yearly return | Value | |||||
|---|---|---|---|---|---|---|---|
Estimates from the rate Treasury set for bonds issued now. Later rates may differ.
I Bond rate history
The rate set each May and November: the composite, its fixed part, and annualized inflation.
| Bonds issued from |
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How I Bonds work
- Term
- Earns interest for 30 years, or until you cash it in.
- How it pays
- A fixed rate for life plus an inflation rate that resets every May and November. Interest is added to the bond's value.
- Buying
- From $25 to the cent, up to $10,000 per person each calendar year.
- Cashing in
- Not in the first 12 months. Before 5 years you give up the last 3 months of interest.
- Taxes
- Federal income tax, which you can defer until you cash in. Exempt from state and local income tax.
How this calculator works
An I Bond earns its composite rate, compounded every six months. The first six months use the rate Treasury set for bonds issued now; later periods combine the same fixed rate with your assumed inflation.
Yearly return is the value at redemption turned into an annual rate; per year is the interest divided evenly over the years held. Rows under five years include the penalty of the last three months of interest.
Ready to buy I Bonds?
You can buy I Bonds directly from the U.S. government at TreasuryDirect.
Treasury Calculator is an independent site and is not affiliated with the U.S. government.