Skip to main content
I bond: October or November?by plusbeauxjours

Not affiliated with the U.S. Treasury, TreasuryDirect or BLS.

What's my I bond worth?

Exact value for any I bond since 1998, with the 3-month penalty, the way TreasuryDirect calculates it.

Official Rates announced through May 2026 ·later dates are a Projection ·Checked .

Issue month (on your bond or in TreasuryDirect)

The purchase price, $25 to $10,000 (electronic bonds to the cent; paper bonds $50 and up).

Value as of

Bonds are valued on the 1st of each month. Up to 30 years after the issue month.

Inflation after April 2027 (same as Nov 2026)Assumption
Inflation rate for every announcement after April 2027

Only matters for dates after the rates Treasury has announced. Nov 2026 uses 1.63% (forecast).

Nothing you type leaves your browser.

Your bond's value

Worth on Oct 1, 2026 Official

$1,104.00

If you cash in then: $1,091.60 (after the 3-month penalty)

Interest earned (before any penalty)
$104.00
3-month penalty if cashed then
−$12.40
Rate on that dateOfficial
4.66%
Rate changes next on
Nov 1, 2026
No penalty from
May 1, 2029
Stops earning (30 years)
May 1, 2054
Fixed rate
1.30%
Age on that date
2 years 5 months

TreasuryDirect shows this value in your account. Paper bonds: use its Savings Bond Calculator (opens in a new tab).

How the value is calculated

Treasury values every I bond from a $25 unit. Each month the unit grows by the bond's current composite rate (value × (1 + rate ÷ 2) to the power of months ÷ 6), rounded to the cent, and every 6 months the result becomes the new starting value. Your bond's value is the unit value times your amount ÷ $25, rounded to the cent. Before 5 years, cashing in costs the last 3 months of interest, but you never get back less than you paid.

We checked this method against 34 answers from TreasuryDirect's own Savings Bond Calculator and every cell of its I bond rate chart: they match to the cent. See the formulas and sources.

Sources

  1. TreasuryDirect: I bonds interest rates (opens in a new tab)

    Checked

    Primary source

  2. TreasuryDirect: I bond rate chart (PDF) (opens in a new tab)

    Checked

    Primary source

  3. TreasuryDirect: Cash in a savings bond (opens in a new tab)

    Checked

    Primary source

  4. TreasuryDirect: Savings Bond Calculator (opens in a new tab)

    Checked

    Primary source

  5. 31 CFR Part 359: Series I savings bonds (eCFR) (opens in a new tab)

    Checked

    Primary source