IBondLab

I Bond vs CD Calculator

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

Your I-bond numbers never leave your browser — all math runs locally.
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Try: Purchase year=2023, Purchase amount=1000, CD APY=4.5, Years=5 → $1,402, $1,246, $156, I-bond

How to use

Enter both yields and a term. The calculator grows each and shows which is larger, before the I-bond’s tax edge.

FAQ

Which is safer?

Both are very safe; I-bonds are backed by the U.S. government and have no market risk if held.

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