Savings Bond Calculator

How Do US Savings Bonds Grow?

US Savings Bonds earn interest on the face value over time, with the rate depending on the bond series. Enter the face value, interest rate, and years held in the calculator above to see the current value, interest earned, and total return. Series I bonds earn a composite rate combining a fixed rate and an inflation adjustment that resets every six months. Series EE bonds earn a fixed rate and are guaranteed to double in value if held for 20 years, making them a unique low-risk investment backed by the US government.

Series I Bonds: Inflation-Protected Savings

I bonds protect purchasing power by adjusting their rate with inflation. The composite rate has two components: a fixed rate (set at purchase, lasting the bond life) and an inflation rate (adjusted every May and November based on CPI-U data). When inflation was 9.1% in 2022, I bonds briefly offered a 9.62% annualized rate. In lower-inflation periods, rates may drop to 3-5%. The fixed rate provides a floor - even if inflation goes to zero, you earn the fixed component. Maximum annual purchase: $10,000 per person electronically through TreasuryDirect.gov, plus up to $5,000 in paper bonds with a tax refund.

Series EE Bonds: The 20-Year Doubling Guarantee

EE bonds currently earn a fixed rate of approximately 2.7%, which alone would not double your money in 20 years. However, the Treasury guarantees that EE bonds will be worth at least double the purchase price at the 20-year mark. This guarantee effectively provides a 3.5% annual return if held the full 20 years, regardless of the stated rate. A $10,000 EE bond purchased today is guaranteed to be worth at least $20,000 at the 20-year mark. Cashing before 20 years forfeits the doubling guarantee and yields only the stated interest rate, making early redemption significantly less valuable.

Tax Advantages of Savings Bonds

Interest on savings bonds is exempt from state and local income tax in all states, providing an immediate advantage over CDs and savings accounts that are fully taxable. Federal tax on the interest can be deferred until the bond is redeemed or reaches final maturity (30 years). If used for qualified higher education expenses (tuition and fees at eligible institutions), interest may be completely tax-free at the federal level for married couples filing jointly with modified AGI below $158,650 (2024). This education exclusion makes savings bonds a targeted college savings tool for middle-income families.

Holding Period and Early Redemption Penalties

Savings bonds cannot be redeemed within the first 12 months. Redeeming between 1 and 5 years forfeits the last 3 months of interest as a penalty. After 5 years, there is no penalty. Bonds earn interest for up to 30 years (final maturity). A $10,000 I bond earning 4.5% redeemed at month 18: 18 months of interest earned ($675), minus 3 months penalty ($225), net interest received $450. After 5 years with the same rate: 60 months of interest ($2,250), no penalty. The 12-month lockup and 5-year penalty window make savings bonds a medium-term savings tool, not an emergency fund.

Savings Bonds vs Treasury Bills vs CDs

Savings bonds: state tax exempt, deferred federal tax, inflation protection (I bonds), 20-year doubling (EE), $10,000 annual limit, 12-month lockup. Treasury bills: mature in 4-52 weeks, auctioned at a discount, highly liquid after purchase, state tax exempt, no purchase limit. CDs: FDIC insured, fixed rate and term, taxable at all levels, early withdrawal penalty, no inflation adjustment. For savings under $10,000/year, I bonds offer the best combination of inflation protection and tax advantage. For larger amounts needing liquidity, T-bills provide competitive yields with easier access. CDs suit specific-date goals where the fixed rate and FDIC insurance provide certainty.

How Do You Buy and Manage Savings Bonds?

Electronic savings bonds are purchased exclusively through TreasuryDirect.gov using a linked bank account. Create an account (free), fund it, and buy I or EE bonds in any amount from $25 to $10,000 (electronic bonds allow penny increments). Paper I bonds are available only by directing a portion of your federal tax refund using IRS Form 8888 (up to $5,000). TreasuryDirect tracks your bonds, current values, and interest earned. Older paper bonds (EE, E, I) can be converted to electronic form through TreasuryDirect. Check the value of legacy paper bonds using the Treasury savings bond calculator at TreasuryDirect.gov.

What Happens at Maturity?

Savings bonds stop earning interest at final maturity (30 years from issue date). After maturity, the bond retains its value but generates zero additional return. Holding a matured bond is equivalent to keeping cash under a mattress - the money loses purchasing power to inflation every year. The Treasury does not automatically notify you when bonds mature. Check your TreasuryDirect account or use the online bond calculator to identify any matured bonds. Series EE bonds issued before May 2005 may have already reached their 20-year doubling and could be approaching or past the 30-year maturity. Redeem matured bonds promptly and redirect the proceeds into a productive savings or investment vehicle.

Frequently asked questions