Series I savings bonds · redemption timing
When should you
cash out your I bond?
Enter the month your bond was issued and what you paid. Get its exact rate history, an estimated value, the 3-month early-withdrawal penalty, and the one thing most guides only describe in words — the best month to redeem, so the penalty lands on your lowest-rate months. Everything runs in your browser.
$11,873.43 estimated value today
Cash out today (est.): $11,779.76 after a $93.67 early-withdrawal penalty
Best time to redeem
Before 5 years, redeeming costs the last 3 months of interest
Your next rate (effective November 2026) has not been announced yet — Treasury sets it on the next May 1 / Nov 1. The penalty is always the most recent 3 months, so the best time to cash out early is after a high-rate stretch has been banked and a lower-rate stretch is the one being forfeited. The penalty ends for good at 5 years (May 2027). Interest posts on the 1st of each month, so the value only changes then — cash out on the 1st (or the first business day after) and never lose days by waiting later in the month.
Full rate schedule (9 six-month periods)
| # | Period | Composite rate |
|---|---|---|
| 1 | May 2022 – October 2022 | 9.62% |
| 2 | November 2022 – April 2023 | 6.48% |
| 3 | May 2023 – October 2023 | 3.38% |
| 4 | November 2023 – April 2024 | 3.94% |
| 5 | May 2024 – October 2024 | 2.96% |
| 6 | November 2024 – April 2025 | 1.90% |
| 7 | May 2025 – October 2025 | 2.86% |
| 8 | November 2025 – April 2026 | 3.12% |
| 9 | May 2026 – October 2026 · now | 3.34% |
Dollar amounts are estimates for planning; rates and dates are exact. For the official value to the cent, use TreasuryDirect. Informational only — not financial advice. How it’s computed →
Informational tool, not financial advice. Dollar amounts are estimates — confirm the official value on TreasuryDirect.
What it shows
One date in, the whole timing picture out
Best month to cash out
Because the penalty is always the last 3 months of interest, when a rate drop is coming the tool points to the exact month to redeem so you forfeit the cheap months — not the expensive ones.
The 3-month penalty, in dollars
Redeem before 5 years and you give back the most recent 3 months of interest. See the estimated amount and the date it disappears for good.
Current & next rate
Your bond's composite rate now and what it becomes on its next 6-month anniversary — or “not yet announced” when Treasury hasn't set it.
Estimated value today
Your principal compounded through every period's real composite rate. An estimate for planning; the official figure is on TreasuryDirect.
Every key date
The 12-month lock, the 5-year mark when the penalty ends, and 30-year final maturity — all measured from your issue month.
Nothing leaves your browser
100% static page, pure client-side JavaScript. No backend, no upload, no logs — and no account needed.
Open methodology
Every number, in the open
No black box. Here is exactly how each value is computed, from official Treasury rate tables — so you can verify and trust it.
- Fixed rateSet for the 6-month window in which the bond was issued and fixed for its entire 30-year life. Taken from the Treasury fixed-rate table by issue month.
- Semiannual inflation rateAnnounced every May 1 and Nov 1. A bond's 6-month period uses the rate that was in effect when that period began (so an issue month other than May/Nov picks up the previous announcement).
- Composite ratefixed + (2 × semiannual inflation) + (fixed × semiannual inflation ÷ 100), rounded to 2 decimals and floored at 0%. Recomputed for every one of the bond's 6-month periods.
- Value estimatePrincipal compounded by each completed period's semiannual rate (composite ÷ 2), with the current partial period accrued month-by-month. Rounded to cents. An estimate — Treasury rounds per $25 with its own rules.
- 3-month penaltyFor redemptions in months 12–59, the forfeited amount equals the interest earned in the most recent 3 months — computed as today's value minus the value three months earlier.
- Key dates12-month lock, the 5-year mark when the penalty ends, and 30-year final maturity are all measured exactly from the issue month.
- Best redemption monthBecause the penalty is the last 3 months, when a known rate drop is ahead the tool points to the month 3 periods into the lower rate; it always reminds you interest posts on the 1st.
Stated plainly: the rates and dates are exact, taken from the U.S. Treasury Fiscal Data tables (latest period: May 2026 — 0.90% fixed, 1.67% semiannual inflation, 4.26% composite). The dollar value and penalty are estimates — Treasury rounds to the penny per $25 with its own rules, so for the official figure use TreasuryDirect. This tool is informational and is not financial advice.
Frequently asked questions
What does ibondrate do?
You enter the month a US Series I savings bond was issued and how much you paid. It works out the bond's exact rate history, an estimate of what it is worth today, the 3-month early-withdrawal penalty if you cash out before 5 years, and — the part most pages only describe in prose — the best month to redeem so that penalty falls on the lowest-rate months. Everything runs in your browser.
When can I cash an I bond, and what is the penalty?
You cannot redeem at all in the first 12 months. From month 12 through the end of year 5, redeeming costs you the most recent 3 months of interest. From 5 years onward there is no penalty and you keep every cent. The bond stops earning at 30 years. ibondrate shows the exact dates for all of these from your issue month.
When is the best time to cash out an I bond?
Two rules. First, interest is added on the 1st of each month and the value does not change until then, so redeem on the 1st (or the first business day after) — waiting until later in the same month gains nothing. Second, because the penalty is always the last 3 months of interest, if your rate is about to drop you usually do better holding until you are 3 months into the new, lower rate, so the penalty eats the cheap months instead of the expensive ones. ibondrate computes the specific month for your bond.
How is the composite rate calculated?
An I bond combines a fixed rate (set when you buy and fixed for the life of the bond) with a semiannual inflation rate (reset every May 1 and Nov 1). The composite annual rate = fixed + (2 × semiannual inflation) + (fixed × semiannual inflation ÷ 100), then floored at 0% so the bond never loses value. Your bond's rate changes every 6 months on its own issue-month anniversary, using whichever inflation rate was in effect when that 6-month period began.
Is the dollar value exact?
The rates, dates and timing are exact. The dollar value and penalty are close estimates: they use the published composite-rate method and monthly compounding, but Treasury rounds to the penny on a per-$25 basis with its own conventions. For the official figure to the cent, use the TreasuryDirect savings-bond value lookup or your TreasuryDirect account. ibondrate is for planning the timing, not for filing.
Where does the rate data come from?
The fixed-rate and semiannual-inflation tables come from the U.S. Treasury "Fiscal Data" I Bonds Interest Rates dataset and are cross-checked against the official TreasuryDirect rate announcements. The most recent period covered is May 2026 (0.90% fixed, 1.67% semiannual inflation, 4.26% composite). Rates beginning after the latest announcement are shown as "not yet announced".
Is this financial advice?
No. ibondrate is an informational calculator that does arithmetic on published Treasury rates — like a tax or mortgage calculator. It does not know your tax situation, goals, or other holdings and does not tell you whether to buy, hold, or sell. For decisions about your money, confirm figures on TreasuryDirect and consider talking to a licensed professional.
Is my data private?
Yes. This is a static page and every calculation happens in your browser with JavaScript. Your issue date and amount are never sent to a server, there is no backend, and nothing is logged.