I-Bond Calculator
Estimate your I-Bond growth over time
Maximum $10,000 per person per year (electronic)
Must hold minimum 1 year. Penalty if cashed before 5 years.
Historical average ~2.5%. Recent years have been higher.
Early Redemption Penalty
If you cash an I-Bond before 5 years, you lose the last 3 months of interest. You cannot cash I-Bonds at all during the first 12 months.
Estimated Value After 5 Years
$13,528
$3,528 in interest (6.23% avg/yr)
Estimated Composite Rate
6.23%
Total Interest Earned
$3,528
Year-by-Year Breakdown
| Year | Balance | Interest | Net Value* |
|---|---|---|---|
| Year 1 Penalty | $10,623 | +$623 | $10,458 |
| Year 2 Penalty | $11,285 | +$662 | $11,109 |
| Year 3 Penalty | $11,988 | +$703 | $11,801 |
| Year 4 Penalty | $12,735 | +$747 | $12,536 |
| Year 5 | $13,528 | +$793 | $13,528 |
*Net value accounts for 3-month interest penalty if cashed before 5 years
Understanding I-Bonds
Safe & Government-Backed
I-Bonds are backed by the full faith and credit of the US government. They're one of the safest investments available—you can't lose your principal.
Inflation Protection
The inflation rate component adjusts every 6 months based on the CPI. When inflation rises, your I-Bond rate rises too.
Tax Advantages
Interest is exempt from state and local taxes. Federal tax can be deferred until redemption. May be tax-free if used for education.
Historical I-Bond Rates
See how rates have changed over recent periods
| Period | Fixed Rate | Inflation Rate | Composite Rate |
|---|---|---|---|
| Nov 2024 - Apr 2025 | 1.2% | 1.47% | 2.67% |
| May 2024 - Oct 2024 | 1.3% | 1.48% | 2.75% |
| Nov 2023 - Apr 2024 | 1.3% | 1.97% | 5.27% |
| May 2023 - Oct 2023 | 0.9% | 1.69% | 4.3% |
| Nov 2022 - Apr 2023 | 0.4% | 3.24% | 6.89% |
| May 2022 - Oct 2022 | 0% | 4.81% | 9.62% |
Key I-Bond Rules
Purchase Limits
$10,000 electronic per person per year. Additional $5,000 with tax refund.
Holding Period
Minimum 1 year. Lose 3 months interest if cashed before 5 years.
Rate Changes
Fixed rate set at purchase (never changes). Inflation rate updates May 1 & Nov 1.
Where to Buy
Only through TreasuryDirect.gov
How to Buy I-Bonds
I-Bonds can only be purchased directly from the US Treasury:
Visit TreasuryDirect.gov