IBondLab

U.S. Series I savings bond values, penalties and comparisons — instant, private.

Your I-bond numbers never leave your browser — all math runs locally.

I-Bond Tools

See accrued interest on a Series I savings bond.

Find the redemption value of an I-bond today.

Current value of a Series I savings bond.

The composite rate behind your I-bond’s growth.

Early-redemption penalty on an I-bond held under 5 years.

Value of an I-bond at its 30-year maturity.

What you get redeeming an I-bond early.

Value of a gifted I-bond over time.

Value of a 2023 Series I savings bond purchase.

Value of a 2024 Series I savings bond purchase.

Value of a 2025 Series I savings bond purchase.

Compare an I-bond with a bank CD over time.

Compare an I-bond with Treasury Inflation-Protected Securities.

Build a yearly I-bond ladder and see its value.

Federal and state tax treatment of I-bond interest.