Treasury Bill Calculator

Calculate T-bill purchase price, interest earned, and equivalent APY from discount rate.
$
%

Purchase Price

$9,747.22

Interest Earned

$252.78

Equivalent APY

5.20%

T-Bill Details

Face Value$10,000.00
Purchase Price$9,747.22
Interest Earned$252.78
Term (182 days)26 weeks

Use the Treasury Bill Calculator above to calculate your results. Enter your values and see instant results — all calculations run in your browser.

Disclaimer: This calculator is for informational purposes only and does not constitute tax, financial, or legal advice. Results are estimates based on the information you provide and current rates. Always consult a qualified tax professional or financial advisor for advice specific to your situation.

How It Works

Our Treasury Bill Calculator simplifies understanding your T-bill investments. It accurately determines the purchase price, interest earned, and the equivalent Annual Percentage Yield (APY) based on the discount rate you input. This tool is crucial for comparing T-bill returns against other investment opportunities, especially considering various economic forecasts for 2026.

The calculator utilizes standard T-bill pricing methodologies. The purchase price is calculated as Face Value * (1 - (Discount Rate * Days to Maturity / 360)). Interest earned is simply the Face Value minus the Purchase Price. The equivalent APY is derived by annualizing the interest earned relative to the purchase price: ((Face Value - Purchase Price) / Purchase Price) * (365 / Days to Maturity).

When using this calculator, remember that T-bills are sold at a discount, not at face value. A common mistake is to confuse the discount rate with the actual yield; our calculator helps clarify this by providing the equivalent APY. Be mindful that while T-bills are considered very low-risk, their returns, like all investments, are subject to prevailing market conditions.

Example: Investing in a 2026 T-Bill

  1. 1 Imagine you are considering purchasing a 26-week (182-day) T-bill with a face value of $10,000. The current discount rate offered by the Treasury for a similar maturity in early 2026 is 5.15%.
  2. 2 Using our calculator, input a Face Value of $10,000, Days to Maturity of 182, and a Discount Rate of 5.15%. The calculator will then apply the formulas: Purchase Price = $10,000 * (1 - (0.0515 * 182 / 360)) and subsequently calculate the interest and APY.
  3. 3 The calculator reveals a Purchase Price of $9,739.58, Interest Earned of $260.42, and an equivalent APY of approximately 5.43%.
  4. 4 This means you would pay $9,739.58 today and receive $10,000 in 182 days, effectively earning $260.42. The 5.43% APY provides a more accurate picture of your annual return, making it easier to compare against other investment options available in 2026, such as a high-yield savings account or certificate of deposit.

Source: SEC · Last updated: April 2026

Frequently Asked Questions

How do Treasury bills work?
T-bills are short-term government securities sold at a discount and redeemed at face value. You buy a $1,000 T-bill for, say, $975 and receive $1,000 at maturity. The $25 difference is your interest. Maturities range from 4 to 52 weeks.
How do I buy Treasury bills?
Buy directly from TreasuryDirect.gov with no fees, or through a brokerage account. TreasuryDirect requires a minimum of $100. Purchases at auction are non-competitive bids, meaning you accept the prevailing rate. You can also buy T-bills on the secondary market through brokers.
Are Treasury bills taxed?
T-bill interest is subject to federal income tax but exempt from state and local taxes. This state tax exemption can make T-bills more attractive than CDs or savings accounts in high-tax states. Report the interest on your federal return in the year the T-bill matures.

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