Treasury bill calculator
Calculate what you pay for a US Treasury bill and what you earn at maturity. A $10,000 26-week bill at a 4% discount rate costs about $9,797.78 and yields 4.14%.
Prefilled with the latest 13-week bill discount rate, 3.99% on Oct 30, 2026, from US Treasury daily bill rates.
Purchase price
$9,899.14
Interest at maturity
$100.86
Investment yield
4.087%
How the treasury bill calculator works
Price from the discount rate
T-bills are quoted as a bank discount rate on a 360-day year. The price per $100 of face value is 100 × (1 − discount rate × days ÷ 360). You pay that price today and receive the full face value at maturity.
Worked example
A $1,000 26-week bill (182 days) at a 5% discount rate costs $974.72. At maturity you receive $1,000, so you earn $25.28. A 52-week bill at the same rate costs $949.44 and earns $50.56.
Why the investment yield is higher than the discount rate
The discount rate is calculated on face value and a 360-day year, while the investment yield is calculated on the price you actually paid and a 365-day year. In the example above, the 5% discount rate is equivalent to an investment yield of about 5.20%, which is the number to compare with savings accounts and CDs.
Using the result
Check current discount rates from recent Treasury auctions, enter them here, and compare the investment yield with other low-risk options. Remember that T-bill interest is exempt from US state and local income tax, which can make them more attractive than a bank account paying the same rate.
Frequently asked questions
How are Treasury bills priced?+
T-bills are sold at a discount to their face value and pay the full face value at maturity. The price is face value x (1 - discount rate x days / 360). The difference between the price and face value is your interest.
What is the difference between the discount rate and the investment yield?+
The discount rate is quoted on face value using a 360-day year. The investment yield (also called the coupon-equivalent or bond-equivalent yield) is based on the price you actually pay and a 365-day year, so it is always a bit higher and is better for comparing with savings accounts and bonds.
How much does a $10,000 26-week T-bill cost at a 4% discount rate?+
It costs about $9,797.78. At maturity you receive $10,000, earning $202.22, an investment yield of 4.139%.
Are Treasury bills taxed?+
Interest on US Treasury bills is subject to federal income tax but exempt from state and local income taxes.
Related
Results are estimates for illustration only and are not financial advice. See our terms of use.