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I Bond Return Calculator

Composite rate and value of a US I bond.

Composite rate
4.22%
annual
Value after 12 months
$10,422
Interest earned
$422
Early-redemption penalty
$105

I bond rules

  • Buy at TreasuryDirect.gov, $25 minimum, $10,000/yr per person
  • Cannot redeem in the first 12 months
  • Redeem before 5 years: forfeit the most recent 3 months of interest
  • Hold up to 30 years; rate resets every 6 months
  • Federal tax only on interest (no state/local). Tax-deferred until redeemed

Composite rate = fixed + 2·inflation + fixed·inflation (semi-annual rates). Fixed rate is set at purchase and locked for the life of the bond. Inflation rate adjusts twice a year. Look up current rates at TreasuryDirect.

About

I bonds combine a fixed rate (set at purchase, locked for life) with an inflation rate (resets every 6 months). Enter both rates and your hold period to project value, interest earned, and the early-redemption penalty.

How to use

  1. Enter purchase amount and rates.
  2. Pick hold period.

FAQ

How do I buy I bonds?+

TreasuryDirect.gov, $25 minimum, $10,000/year per Social Security number. Tax refunds can buy an additional $5,000 in paper bonds.