I Bond Yield Calculator 2026
Calculate your I Bond composite rate, monthly interest earned, and see how your yield resets semi-annually. Based on the Nov 2025 fixed rate of 1.30% from TreasuryDirect.gov.
How I Bond Composite Rate Works
Series I Savings Bonds earn interest based on a composite rate combining two components: a fixed rate and a semiannual inflation rate tied to the Consumer Price Index (CPI-U). The formula is: Composite = fixed + (2 × semiannual CPI) + (fixed × semiannual CPI). The fixed rate is set at purchase and never changes for the life of the bond. The inflation component resets every six months — in May and November — based on CPI-U data reported by the Bureau of Labor Statistics.
Bonds purchased from November 2025 through April 2026 carry a fixed rate of 1.30%, the highest fixed rate since 2007. This locks in a real return above inflation for the entire holding period, regardless of future CPI resets. Source: TreasuryDirect.gov. Last updated: May 2026.
I Bond Rate Reset Schedule
| Purchase Month | Reset Months | First Reset |
|---|---|---|
| January | January / July | July (6 months later) |
| February | February / August | August |
| March | March / September | September |
| November–April (2025–26) | Varies by month | Fixed at 1.30% for life |
I Bonds vs HYSA vs Treasury Bills 2026
As of May 2026, high-yield savings accounts offer around 4.5–5.0% APY, while 6-month Treasury Bills yield approximately 4.2–4.6%. I Bonds with the 1.30% fixed rate plus current CPI inflation offer roughly 4.28% composite. The key advantage of I Bonds is that the fixed component persists for 30 years — if inflation rises again, your yield automatically rises too, unlike a locked CD or T-Bill. The trade-off: 12-month lockup (no redemption in year one) and a 3-month interest penalty if redeemed before 5 years. For funds you won't need for at least 5 years, I Bonds with a high fixed rate are a compelling inflation hedge.
Frequently Asked Questions
What is the current I Bond fixed rate in 2026?
The fixed rate set in November 2025 is 1.30% and applies for the life of bonds purchased from November 2025 through April 2026. The composite rate changes every six months when the inflation component resets. Check TreasuryDirect.gov for the latest rates.
How is the I Bond composite rate calculated?
Composite rate = fixed rate + (2 × semiannual inflation rate) + (fixed rate × semiannual inflation rate). For example, with fixed 1.30% and semiannual CPI of 1.48%, composite = 0.013 + 0.0296 + (0.013 × 0.0148) = 4.28% annualized.
When does my I Bond rate reset?
Your I Bond rate resets every six months based on your purchase month. If you bought in March, your rate resets each March and September. The fixed component never changes, but the inflation component updates each May and November based on CPI-U data.
What is the I Bond purchase limit per year?
Individuals can buy up to $10,000 in electronic I Bonds per year via TreasuryDirect, plus an additional $5,000 in paper I Bonds using a federal tax refund. Trusts, LLCs, and other entities may have separate limits.
Can I lose money on I Bonds?
No. I Bonds are backed by the U.S. government and never lose nominal value. The composite rate cannot go below 0% even if deflation occurs. However, if you redeem before 5 years, you forfeit the last 3 months of interest.