Treasury Bill (T-Bill) Calculator
Calculate T-bill returns: purchase price from the discount rate, interest earned, and the investment rate (bond-equivalent yield) to compare with savings.
For information and education only — not financial advice. Results are estimates based on the numbers you enter; check important decisions with a qualified professional.
How to use
- 1Enter the face value, term in days and the auction discount rate.
- 2See the price you pay, interest earned and the equivalent annual yield.
How it's calculated
Price = face × (1 − discount rate × days ÷ 360). Investment rate (bond-equivalent) = (face − price) ÷ price × 365 ÷ days.
Frequently asked questions
Why are there two rates?
TreasuryDirect quotes the discount rate (based on face value and a 360-day year) and the investment rate, which is comparable to savings APYs and CD yields.
Are T-bills taxed?
Interest is subject to US federal income tax but exempt from state and local income tax.
What terms are available?
4, 6, 8, 13, 17, 26 and 52 weeks.