Treasury Bill Calculator

When price is entered, purchase cost before fees equals face value multiplied by price per $100 divided by 100. When a bank discount rate is entered, the modeled price per $100 is 100 × [1 − discount rate × days ÷ 360]. Maturity interest equals face value minus purchase cost before fees.

The bank discount rate uses face value and a 360-day year. The investment rate shown here uses purchase price and a 365-day year. Effective annual yield compounds the holding-period return over a hypothetical 365-day year; it assumes equivalent reinvestment is continuously available and therefore is not a promised return.

The tax estimate applies only the entered federal marginal rate to maturity interest and subtracts entered fees. Treasury interest is generally exempt from state and local income taxes, so the state/local figure is displayed only as an illustrative exemption amount. The calculator omits secondary-market price changes, accrued-interest reporting details, broker spreads, auction rounding, changing reinvestment rates, and individual tax circumstances.