US T-Bill Calculator

Estimate the return on a U.S. Treasury bill based on face value, purchase price, and days to maturity. Results include both market quote style and investor yield style outputs.

T-bills are commonly quoted using a face value and sold at a discount.

Amount paid today for the Treasury bill.

T-bills mature in one year or less.

Dollar Discount = Face Value - Purchase Price
Bank Discount Yield = (Discount / Face Value) x (360 / Days)
Investment Yield = (Discount / Purchase Price) x (365 / Days)
If a $10,000 T-bill is purchased for $9,750 and matures in 182 days, the dollar discount is $250, bank discount yield is 4.95%, and investment yield is 5.15%.

What is a U.S. Treasury bill?

A U.S. Treasury bill is a short-term government security that does not pay periodic coupons. Instead, it is bought below face value and redeemed at face value on maturity, with the difference representing the investor return.

What is the bank discount yield?

Bank discount yield is a common quoting method for T-bills. It annualizes the discount relative to face value using a 360-day basis. It is useful for market quoting, but it is not the same as the investor actual return on money invested.

What is investment yield for a T-bill?

Investment yield annualizes the gain relative to the purchase price instead of face value, typically using a 365-day basis. It better reflects the return earned on the actual cash invested.

Why do T-bill yields differ from bond yields?

T-bills are zero-coupon securities with maturities under one year, so their quoting conventions differ from coupon-bearing bonds. There are no periodic interest payments, and the return comes entirely from the discount to face value.