Treasury Bill (T-Bill) Yield Calculator
Calculate a Treasury bill’s discount yield, investment rate (bond-equivalent yield), effective annual yield and interest from face value, price and days to maturity.
- 100% free
- Private in browser
- No signup
- No watermarks
Rate this tool
Be the first to rate — helps others and improves this page.
About Treasury Bill (T-Bill) Yield Calculator
Treasury bills are sold at a discount and mature at face value. Enter the face value, purchase price and days to maturity to see interest earned, the bank discount yield, the investment rate TreasuryDirect reports, and the effective annual yield.
How to use Treasury Bill (T-Bill) Yield Calculator
- Enter the face value of the bill.
- Enter the price you paid (or the auction price per $100 × face value ÷ 100).
- Enter the days until maturity to see each yield measure.
Key features
- Bank discount yield (360-day basis)
- Investment rate / bond-equivalent yield (365-day basis)
- Effective annual yield with compounding
- Interest earned at maturity
- Runs in your browser
Frequently asked questions
- What is the discount yield?
- Discount yield = (face − price) ÷ face × 360 ÷ days. It is the traditional money-market quote and understates the true return.
- What is the investment rate?
- Investment rate = (face − price) ÷ price × 365 ÷ days. It is the bond-equivalent yield TreasuryDirect reports for bills and is better for comparing with CDs and savings accounts.
- What is the effective annual yield?
- The return if you reinvested in identical bills for a full year: (face ÷ price)^(365 ÷ days) − 1.
- Is T-bill interest taxable?
- Interest is subject to federal income tax but exempt from state and local income taxes.
- Is my data private?
- Yes. All calculations stay in your browser.
Related In-Depth Guides
Learn practical workflows, real-world examples, and expert tips in our comprehensive guides:
Home Remodeling Material Takeoff Guide: Tile Grout, Drywall Mud & Kitchen Cabinet Runs
Professional contractor takeoff formulas for interior renovations. Accurately estimate tile grout bags, drywall joint compound for Level 4 finishes, and modular kitchen cabinet spacing.
How to Size a Home Emergency Generator: Running vs Surge Watts & Propane Runtime
Complete electrical guide to calculating running watts, motor startup surge wattage, transfer switches, and fuel consumption for winter storms and outages.
Patio Paver & Retaining Wall Installation Guide: Base Gravel, Sand & Block Calculations
Avoid settling, cracking, and water pooling. Step-by-step math for paver patterns, 4-6 inch aggregate base, 1-inch bedding sand, and drainage gravel.