Treasury Bill Calculator
Find T-bill discount and investment yields.
Results update as you type.
How it works
Treasury bills (T-bills) are short-term US government securities sold at a discount to their face value and redeemed at full face value at maturity, and this calculator finds their yield and profit. You enter the face value, the purchase price, and the days to maturity, and it returns the discount yield, the investment yield (also called the bond-equivalent yield), and the dollar profit. Because a T-bill pays no periodic interest, your entire return comes from buying below face value and receiving the full amount at maturity. Two yield measures are standard and often confused. The discount yield is the traditional quoting convention: it divides the discount by the face value and uses a 360-day year, which understates the true return. The investment yield divides the profit by the price you actually paid and uses a 365-day year, giving a more accurate return that can be compared fairly with other investments like CDs or bonds. T-bills are considered among the safest investments, backed by the US government, and their interest is exempt from state and local income tax. They are popular for parking cash safely for terms from a few weeks to a year. Enter the face value, price, and days to maturity to see the yields.
Discount yield = (face−price)/face × 360/days; investment yield = (face−price)/price × 365/days
Treasury bills are sold at a discount and pay full face value at maturity. The discount yield uses the face value and a 360-day year, while the investment yield (bond-equivalent yield) uses the purchase price and a 365-day year, giving a truer return that is comparable to other investments.
Source:Money market yield conventions
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter face value, purchase price and days to maturity.
- 2
Adjust the options
Fine-tune any options to match your situation.
- 3
Read your result
Investment yield (BEY) updates instantly as you type — no button to press.
Frequently asked questions
How do Treasury bills work?
Treasury bills are short-term government debt sold at a discount to face value and paying full face value at maturity, with no periodic interest. Your return is the difference between the discounted price you pay and the face value you receive. Maturities range from a few weeks to 52 weeks, making T-bills a safe place to hold cash short-term.
What is the difference between discount yield and investment yield?
The discount yield is the traditional quote, dividing the discount by the face value over a 360-day year, which understates the real return. The investment yield, or bond-equivalent yield, divides the profit by the price you actually paid over a 365-day year, giving a truer return you can compare to CDs and bonds. The investment yield is higher.
Are Treasury bills a good investment?
T-bills are among the safest investments, fully backed by the US government, making them ideal for preserving capital and holding cash you may need soon. Their yields track short-term interest rates and are usually lower than riskier assets over the long run, so they suit safety and liquidity goals more than long-term growth.
Are Treasury bill earnings taxed?
The interest earned on Treasury bills is subject to federal income tax but is exempt from state and local income taxes, which can be a meaningful advantage in high-tax states. The gain is treated as interest income rather than a capital gain. Consider this tax treatment when comparing T-bill yields to other short-term options.
How is T-bill profit calculated?
The profit is simply the face value minus the purchase price, since you buy at a discount and receive full face value at maturity. Buying a $1,000 bill for $980 yields a $20 profit over the holding period. The calculator shows this profit alongside the annualized yields so you can compare across different bills and terms.