I Bond Calculator

The TreasuryDirect composite rate is: fixed rate plus 2 times the semi-annual inflation rate plus (fixed rate times semi-annual inflation rate). The 2x multiplier annualizes the 6-month inflation rate Treasury publishes every May 1 and November 1. With a 1.2% fixed rate and a 2.0% semi-annual inflation rate, the composite is 5.224% annually. A negative inflation component can reduce the composite rate, but the composite rate cannot fall below zero. Treasury assigns an issue date on the first day of the purchase month, then resets the rate every six months from that issue month.

An individual can buy up to $10,000 in electronic I Bonds per calendar year through TreasuryDirect. The federal tax-refund program for buying up to $5,000 in paper I Bonds ended on January 1, 2025, so it is no longer an additional current purchase route. Separate entity and gift rules have their own requirements and limits.

I Bonds issued before February 2003 can be redeemed after six months. Bonds issued in February 2003 or later have a 12-month minimum holding period. Both periods are measured from the issue date, which is the first day of the purchase month. The calculator applies the correct gate from the issue month, then counts down to the five-year penalty cutoff when applicable.

An eligible bond redeemed before five years (60 months) forfeits the most recent three months of accrued interest. Eligibility begins after six months for issues before February 2003 and after 12 months for later issues. Bonds held five years or longer pay all accrued interest with no early-redemption penalty.

I Bond interest is subject to federal income tax and exempt from state and local income tax. You can generally defer federal reporting until redemption or final maturity, or elect annual reporting. A Section 135 education exclusion depends on ownership, age, qualified expenses, other education benefits, and income limits and may be partial. The calculator's toggle applies a full exclusion scenario and does not test those requirements.