Introduction
A treasury bond is a loan you give to a government. In return, the government pays you interest (called a coupon) a few times a year, then pays back your money at the end. This Treasury Bond Calculator shows you exactly what that deal is worth.
Enter your settlement date, maturity date, face value, coupon rate, and payment frequency. The calculator then works out:
- Clean price and dirty price — what you pay, with and without accrued interest
- Accrued interest — the interest earned since the last coupon date
- Yield to maturity (YTM) and current yield — see also our focused Bond Yield Calculator
- Duration, DV01, and convexity — how much the price moves when rates change
- Total return before and after withholding tax
You can work in two directions. Pick Solve for Price to find the price from a market yield (the same job as our Bond Value Calculator). Pick Solve for Yield to find the YTM from a price you already know.
You also get a full coupon payment schedule, charts of your cash flows, and a step-by-step math solution so you can see how every number was found. Choose your currency and day count convention to match your market. If you are comparing government paper with other safe options, run the numbers through the CD Calculator, the HYSA Calculator, or the Savings Bond Calculator too.
How to Use Our Treasury Bond Calculator
Enter your bond's dates, face value, coupon rate, and tax rate, then pick whether you want to solve for price or yield. The treasury bond calculator gives you the clean price, dirty price, accrued interest, yield to maturity, duration, DV01, convexity, your gross and after-tax return, plus a full coupon schedule and charts.
Value Date (Settlement): Pick the day you buy or settle the bond. All pricing starts from this date. Use the Business Days Calculator if you need to roll settlement to the next trading day.
Maturity Date: Pick the day the bond pays back your principal. This date and the term below stay in sync.
Investment Term: Type how many years you hold the bond. The maturity date updates on its own when you change it. The Date Duration Calculator helps if you want the exact day count between two dates.
Day Count Convention: Choose how days are counted: Actual/Actual (ICMA), Actual/365, Actual/360, or 30/360. This sets your accrued interest and the first part-period.
Face Value (Par): Pick your currency, then type the principal the bond pays back at maturity, such as 1,000,000. For cross-border holdings, the Currency Calculator converts your proceeds.
Coupon Rate (annual): Type the yearly interest rate printed on the bond, like 12.50 for 12.5%.
Coupon Frequency: Choose how often coupons are paid: semi-annual (2 times a year, the treasury standard), annual, or quarterly.
Withholding Tax Rate: Type the tax rate taken off each coupon. Use 0 for tax-free or infrastructure bonds. Our Tax Withholding Calculator and Effective Tax Rate Calculator can help you pick the right figure.
Calculation Direction: Choose "Solve for Price" to find the bond price from a yield, or "Solve for Yield" to find the YTM from a price you already know.
Market Yield / YTM (annual): In Price mode, type the market yield you want to use. In Yield mode, the calculator fills this in for you. See the interest rate calculator if you want to back out an implied rate first.
Known Market Price (% of par): In Yield mode, type the price as a percent of par, like 98.50. In Price mode, the calculator fills this in for you.
Price Basis: Say if your known price is a clean price (no accrued interest) or a dirty price (with accrued interest).
Click Calculate to see your results and step-by-step math. Click Reset to go back to the sample values.
What Is a Treasury Bond?
A treasury bond is a loan you give to a government. You pay money today. The government pays you interest twice a year (called a coupon), and gives your money back on the maturity date. Because governments rarely miss payments, treasury bonds are seen as one of the safest places to put money, which is why they often anchor the low-risk slice of a portfolio you might model in the Investment Calculator.
The Main Parts of a Bond
- Face value (par): the amount paid back at the end, like $1,000,000.
- Coupon rate: the fixed yearly interest rate written on the bond. A 12.5% coupon on $1,000,000 pays $125,000 a year.
- Frequency: how often coupons are paid. Most treasury bonds pay twice a year.
- Maturity date: the day the loan ends and the face value is paid back.
- Value date (settlement): the day you actually buy the bond and pay for it.
Price and Yield Move in Opposite Ways
The coupon rate never changes, but market interest rates do. So the price of the bond changes instead. When market rates go up, bond prices fall. When market rates go down, bond prices rise.
- Premium: the coupon is higher than the market yield, so buyers pay more than par.
- Discount: the coupon is lower than the market yield, so buyers pay less than par.
- Par: the coupon and the market yield match, so the price equals face value.
Yield to maturity (YTM) is the total yearly return you earn if you hold the bond to the end and get every payment. It counts both the coupons and any gain or loss between the price you paid and the face value. Under the hood it is an internal rate of return, the same idea used in the IRR Calculator, and the price itself is a discounted cash flow, just like in the NPV Calculator and the DCF Calculator.
Clean Price, Dirty Price and Accrued Interest
Bonds are quoted as a percent of par, like 98.50%. That quote is the clean price. But if you buy between coupon dates, the seller already earned some interest. You pay them for those days. That is accrued interest, and it is worked out the same way as in a Simple Interest Calculator — rate times principal times days over the year basis.
Dirty price = clean price + accrued interest. The dirty price is the real cash you hand over on settlement day.
Day Count Conventions
A day count rule tells you how to count the days in a period. It changes the accrued interest amount. Common rules are Actual/Actual (ICMA), Actual/365, Actual/360 and 30/360. Actual/Actual is the normal choice for government bonds.
Risk Measures: Duration, DV01 and Convexity
- Macaulay duration is the average time, in years, until you get your money back, weighted by the size of each payment. Each weight is a present value, the kind of figure the Present Value Calculator produces.
- Modified duration shows how much the price drops if yields rise 1%. A duration of 4 means the price falls about 4%.
- DV01 is the cash change in price for a move of one basis point (0.01%). Our BPS Calculator is handy for converting basis points to percentages.
- Convexity fixes the small error in duration. Prices bend, they do not move in a straight line. Higher convexity is good for the owner.
Longer bonds and lower coupons mean higher duration, so more price risk when rates move.
Withholding Tax on Coupons
Many countries take a tax straight out of each coupon before it reaches you. A 15% withholding tax on a $62,500 coupon leaves $53,125 in your pocket. Some bonds, like infrastructure bonds in some markets, are tax free. Tax lowers your real return, so always compare bonds after tax, not before. If you sell before maturity, a price gain may also be taxed — check the Capital Gains Tax Calculator and the Income Tax Calculator for your situation.
Current Yield vs. Yield to Maturity
Current yield is just the yearly coupon divided by the price. It is quick but it ignores the gain or loss at maturity. It works much like the Dividend Yield Calculator does for shares. Yield to maturity counts everything, so it is the better number to compare bonds. To put a nominal YTM on the same footing as a quoted savings rate, convert it with the APY Calculator.
Why This Matters
Knowing the price, yield, accrued interest and duration helps you see if a bond is a fair deal, how much cash it will pay you, and how much its value can swing if interest rates change. To judge whether the return is worth keeping, compare it against rising prices using the Inflation Calculator, project reinvested coupons with the Compound Interest Calculator, and see how the payout fits your long-term plan in the Retirement Calculator.