I-Bond Calculator
Explore an approximate value for a new Series I bond. The first six months use the listed issue rate; later six-month rates use your assumption.
Issue-period rates
For bonds issued May 1, 2026–October 31, 2026. Check TreasuryDirect for the latest rate before buying.
Your scenario
$25 minimum; up to $10,000 in electronic I bonds per Social Security or employer ID per calendar year. Prior purchases count toward that cap.
Six-month rate component, repeated after the known first six months. Starting value matches this issue period for comparison; it is not a forecast. Actual inflation rates reset every six months. At this assumption, the later composite rate is 4.26%.
Approximate scenario value
Checking the issue period before showing a scenario.
This is an estimate for a new bond issued in the period shown, not an official redemption value or a valuation of an existing bond. Treasury’s cent-rounding can change the final amount. Check your TreasuryDirect account for a bond’s actual value.
Federal interest may be reported each year or deferred until redemption or maturity. I-bond interest is exempt from state and local income tax.
How Treasury calculates redemption values (31 CFR part 359) ↗