US Treasury Bill Calculator: T-Bill Yield & Price

How the US Treasury Bill Calculator Works

A Treasury bill is a short-term debt security sold by the U.S. Department of the Treasury. It pays no coupon. Instead, you buy it below its par value and the government repays the full amount on the maturity date. The gap between the two is the interest earned, and every number this tool produces comes from that gap. Pair this with the free reit tax equivalent distribution calculator for a fuller picture before you make a decision.

You supply three things: the face value you will be repaid, the purchase price you pay (or the discount rate quoted at auction), and the days to maturity. The tool returns the dollar discount, the price per $100 of face value, the profit at maturity, and the yields described below. Because each yield uses a different base and a different year length, the same bill can honestly show four different percentages.

Why the Yield Looks Different Each Time

Two choices drive the spread between measures. The first is the denominator: face value or the cash you actually invested. The second is the day count: a 360-day year (the money market habit) or a 365-day year. Mix those choices and you get the four measures in the next section, always ordered the same way for a discount bill.

T-Bill Yield Calculator: Four Yield Measures Explained

A bill's return can be expressed in several ways, and each one answers a different question. Keep the four in mind whenever you compare a T-bill with a savings account, a certificate, or a note. Next, open the free cd ladder calculator and enter your own details to see an estimate in seconds.

Bank Discount Yield (the Dealer Quote)

The bank discount yield is the rate quoted at the auction and by dealers. It measures the dollar discount against face value, using a 360-day year:

$$BDY = \frac{F - P}{F} \times \frac{360}{d}$$

Here \(F\) is face value, \(P\) is price, and \(d\) is days to maturity. It is a dealer quote convention rather than a true measure of what your money earns, because it divides by money you never put up. That is why the discount yield always looks a little lower than your real return.

Money Market Yield

The money market yield keeps the 360-day year but divides by the purchase price, so it reflects cash actually invested. Banks call it the CD-equivalent yield because it lines up with certificates of deposit and commercial paper, which follow the same money market convention.

$$MMY = \frac{F - P}{P} \times \frac{360}{d}$$

Bond Equivalent Yield

The bond equivalent yield (BEY) swaps in a 365-day year, making the bill comparable with a semiannual coupon-equivalent return on notes and bonds. For bills of 182 days or fewer the simple form applies; beyond that the Treasury uses a quadratic formula that adjusts for semiannual compounding. This is the investment yield most investors should use when comparing a bill against other fixed-income choices.

$$BEY = \frac{F - P}{P} \times \frac{365}{d}$$

Effective Annual Yield

The effective annual yield assumes your proceeds are reinvested at the same rate for a full year. It is the most generous measure, and it is hypothetical, since the rate you can get next quarter may differ.

$$EAY = (1 + HPR)^{365/d} - 1$$

The holding period return (HPR) inside that formula is simply the profit divided by price over the life of the bill, with no annualization at all.

T-Bill Price Calculator: From Discount Rate to Purchase Price

At auction you rarely see a price. You see a discount rate, and the price follows from it:

$$P = F \times \left(1 - \frac{DR \times d}{360}\right)$$

where \(DR\) is the discount rate. Enter it with the face value and the days to maturity, and the calculator reports the dollar discount you save, the maturity value you receive, and the price per $100 face, the quote style brokers use. A price of 98.89 per $100 means you pay $98.89 for every $100 repaid.

Investment Yield vs Discount Yield

If you already know the price you paid on the secondary market, work in reverse: enter it and read off the rate. The investment yield will always come out higher than the discount rate on the same bill, because the denominator shrinks from face value to price and the year shortens from 360 to 365 days.

Treasury Bills Calculator Inputs and Standard Maturities

Treasury issues bills on a fixed menu of terms, and the presets in the calculator match them. Each is sold at a weekly auction except two that come around every four weeks:

• 4-week (28 days): the shortest term, auctioned weekly and handy for cash management.
• 8-week (56 days): auctioned weekly, usually a hair above the 4-week rate.
• 13-week (91 days): the three-month bill and a widely quoted benchmark.
• 17-week (119 days): auctioned every four weeks.
• 26-week (182 days): the six-month bill, the longest term where the simple BEY formula still applies.
• 52-week (364 days): the longest bill, also auctioned every four weeks.

Treasury also issues cash management bills with irregular terms when it needs funds quickly. For those, skip the preset and type the exact days. Count from the settlement date, not the auction date, and keep the day count consistent across any bills you compare.

4-Week to 52-Week Maturity Presets

The table below holds the discount rate fixed at 4.38% on a $25,000 face value and varies only the term. Notice how the return climbs slowly with maturity even though the quoted discount never moves.

T-Bill Calculator Worked Example: $25,000 for 91 Days

Say you are buying a 13-week bill with a face value of $25,000 at a discount rate of 4.38%, held for 91 days. First the price: $25,000 × (1 − 0.0438 × 91 ÷ 360) = $24,723.21. The dollar discount is therefore $276.79, which is your dollar profit when the bill matures, and the price per $100 face works out to 98.89.

The ordering is exactly what theory predicts: discount yield, then money market yield, then BEY, then the compounded figure. If your alternative is a one-year certificate quoting 4.40% APY, the right comparison is the 4.567% effective annual yield, provided you can roll the money into a new bill at a similar rate.

Pricing a 26-Week Bill with the Treasury Bills Calculator

Dana owes a property tax installment of $18,400 in 182 days, and the money currently sits in a savings account paying about 4.05%. A 6-month certificate at her credit union offers 4.15% APY, so the question is whether a 26-week bill beats it after the arithmetic is done properly.

The latest auction result is a 4.29% discount rate. Dana enters a face value of $18,400, a discount rate of 4.29%, and 182 days to maturity, then presses Calculate. The tool returns a price of $18,000.93, a dollar discount of $399.07, and a price of 97.83 per $100 face. The 4.29% she was quoted is only the bank discount yield. The same bill works out to a 4.385% money market yield, a 4.446% bond equivalent yield, and a 4.496% effective annual yield.

The honest comparison is the 4.496% effective annual yield against the certificate's 4.15% APY, since both are annual compounded figures. That is a $30.37 edge on the same cash, and it lands as a single payment exactly when the tax bill arrives. A 182-day bill is also the longest term where the simple BEY formula applies, so no quadratic adjustment muddies the number.

The next step is concrete: Dana submits a bid for $18,400 of face value through her broker and sets aside $18,000.93 to fund it, instead of opening the certificate.

Treasury Bill vs Treasury Notes and Bonds

A Treasury bill matures in a year or less and has no coupon. Notes run two to ten years and bonds twenty to thirty, and both pay a semiannual interest rate you collect along the way. All three are securities backed by the full faith and credit of the government, which is why they anchor the risk-free benchmark. Interest is state and local tax-free, but you still owe federal income taxes on it.

Who Buys T-Bills

Individual investors use T-bills for emergency funds and tuition money, and institutions and central banks hold them as liquid reserves. If you buy through brokers or directly from TreasuryDirect, the workflow is the same: take the auction discount rate, enter it with your face value and days to maturity, and let the calculator return the price and yield for each rung of a ladder that rolls one maturity into the next. Together with notes and bonds, these instruments are often just called Treasurys, and the bill is the one with the least price movement.

The yield result also tells you where T-bills fit in a portfolio. Compare the bond equivalent figure with the payout on a dividend stock or an ETF: if the bill's guaranteed return covers your cash needs for the next year, a dividend cut matters less to your income, and the sleeve of T-bills lets you size the rest of the investment plan around it. Compared with equities, risk is minimal; compared with bonds, price swings are small because the maturity is short. The tax treatment is the one detail worth checking against your own bracket before you pick a rung.

Limits of a T-Bill Calculator

This tool shows short-term government debt arithmetic on a clean discount price, with no brokerage fees, no accrued interest, and no live auction results. Real T-bills settle on specific dates, and a bill bought on the secondary market may trade a few hundredths away from the figure you enter, so use TreasuryDirect or your broker for the final confirmation on any of the treasury bills you plan to buy. Treat the output as a planning estimate that tells you which maturity and which yield measure deserve a closer look, then verify the actual award price before you commit funds.