Treasury bill price calculator
By Jude Wallis
A Treasury bill's bank discount price is face value times one minus the discount rate times days over the day count. $10,000 at 5 percent for 180 days on a 360 day basis has a $250 discount and a $9,750 price.
T-bill price
$9,750.00
Discount $250.00 on $10,000.00 of face.
- Face
- $10,000.00
- Discount
- $250.00
- Price
- $9,750.00
Amount paid at maturity.
Bank-discount rate quoted on face. 5 here means 0.05.
Days remaining in the discount fraction.
The bank-discount year on this sheet is 360.
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On this page
The formula
is face value, is the bank discount rate, and is days. The examples use a 360 day basis.
Calculate the discount first
On $10,000, a 5 percent discount rate for 180 of 360 days gives a $250 discount. Subtract it from face to get $9,750. How Treasury bills work explains the quotation.
A shorter bill
At 4 percent for 90 of 360 days, the discount on $10,000 is $100. Price is therefore $9,900.
Discount basis is not purchase yield
The quoted discount uses face value and a day count in the numerator. A Treasury bill repays face principal at maturity.
Scope of the price
This identity prices a bill from a bank discount quote and entered day count. Yield measures use different denominators. This is educational material, not financial advice.
Worked examples
\$10,000 at 5 percent for 180 days
Face value is $10,000, bank discount rate is 0.05, term is 180 days, and the basis is 360 days. What are discount and price?
- Discount is , so $250.
- Price is , so $9,750.
A $10,000 face value at 0.05 for 180 days on a 360 day basis has a $250 discount and $9,750 price.
\$10,000 at 4 percent for 90 days
Face value is $10,000, bank discount rate is 0.04, term is 90 days, and the basis is 360 days. What are discount and price?
- Discount is , so $100.
- Price is , so $9,900.
A $10,000 face value at 0.04 for 90 days on a 360 day basis has a $100 discount and $9,900 price.
Applying the quote directly to purchase price
The bank discount amount uses face value. A yield on purchase price is a different calculation.
Common questions
Why does the formula use 360?
These examples use the stated 360 day bank discount basis.
Is discount the same as interest paid periodically?
No. It is the amount subtracted from face value to find purchase price.
Is this financial advice?
No. It is educational material for a bank discount price identity.
Keep reading
This page is educational material, not financial advice. The figures come from the formula shown and assume the inputs you enter hold for the whole term. Your own rate, fees, taxes and timing will differ, so treat the output as arithmetic to check a decision against, not as a recommendation.