Bond Calculator
For bonds traded on a coupon payment date. Solve for any one unknown.
Change "Solve For" above to enter your own value.
Enter bond details to calculate price, yield, face value, or maturity
Results update in real time
This Bond Calculator prices fixed-rate coupon bonds, solves for yield to maturity, and calculates clean and dirty prices when you trade between coupon dates. Bond math piles up fast: semiannual coupons, discount rates per period, accrued interest, day-count rules. One wrong input and your price is off by hundreds of dollars. Read on and you'll also find out what a 5% yield actually means, how clean price differs from what you pay, and how to rerun the numbers when the market price moves.
From this page, you'll learn:
- How to price a bond from face value, coupon rate, yield, and years to maturity
- What yield to maturity (YTM) measures and how it differs from the coupon rate
- Why clean price and dirty price are not the same number on settlement day
- How to switch Solve For to update bond price and instantly see the new yield
How to Use the Bond Calculator
Pick a mode, choose what you want to solve for, and fill in the other fields. Results update as you type.
Coupon Date Mode
- 1. Select Solve For: Bond Price, Yield to Maturity, Face Value, or Years to Maturity.
- 2. Enter face value (par), coupon rate or dollar coupon, and coupon frequency.
- 3. Fill in the remaining inputs. The calculated field shows live with a CALCULATED badge.
- 4. When the market price changes, switch Solve For to Yield and edit the Bond Price field directly.
Settlement Pricing Mode
- 1. Enter face value, coupon, yield, maturity date, and settlement date.
- 2. Choose a day-count convention (30/360, Actual/360, Actual/365, or Actual/Actual).
- 3. Read clean price, dirty price (invoice price), and accrued interest in the results panel.
Worked Example: Marcus prices a corporate bond before buying
Marcus is comparing a corporate bond with a $10,000 face value, a 4.75% annual coupon paid semiannually, 12 years to maturity, and a required yield of 6.25%. He sets Solve For to Bond Price and enters the details.
Face Value
$10,000
Coupon
4.75% semi
Years
12
Yield
6.25%
Result: bond price = $8,746.77. The bond trades below par because the market demands 6.25% while the coupon only pays 4.75%. Marcus now knows exactly what he should pay per bond before fees. Totally worth running the numbers.
What Is Bond Pricing?
Picture a vending machine that spits out $237.50 every six months for twelve years, then hands you $10,000 at the end. How much would you pay for that machine today if you wanted a 6.25% return? That's bond pricing. You're not buying a sticker price. You're buying a stream of future cash and discounting every payment back to today.
Bond pricing is the process of calculating what a fixed-rate coupon bond is worth today by discounting its future coupon payments and face value at a required yield to maturity. The result is the present value of all cash flows the bond will pay before it matures.
Marcus's $8,746.77 figure is not random. The bond promises $237.50 every six months (that's 4.75% of $10,000, split in two) plus $10,000 back at year 12. But Marcus wants 6.25% annually. Each future payment gets discounted harder than the coupon alone would suggest. The gap between coupon rate and yield is what quietly reshapes every bond price you see quoted.
Coupon rate vs yield to maturity
The coupon rate is printed on the bond certificate. It never changes. Yield to maturity (YTM) is what you actually earn if you buy at today's price and hold until maturity, assuming all coupons get reinvested at the same rate. When YTM is higher than the coupon, the bond trades below face value (at a discount). When YTM is lower, it trades above par (at a premium).
So what does a 5% bond yield mean? It means that if you buy the bond at its current price and hold it to maturity, your annualized return works out to roughly 5%, counting coupons and the return of principal. It does not mean the bond pays $5 for every $100 of face value each year unless the coupon rate also happens to be 5%.
Clean price, dirty price, and accrued interest
Most bond quotes you see on a screen are clean prices. They exclude interest that has built up since the last coupon payment. When you actually buy, you pay the dirty price (also called the invoice price), which equals clean price plus accrued interest. Note that our Settlement Pricing mode handles this split automatically once you enter maturity and settlement dates.
Bond traders live in clean prices. Back-office settlement teams live in dirty prices. If you only look at one, you'll wonder why your trade confirmation doesn't match the quote you saw five minutes earlier. Now you know why both numbers exist.
The Bond Price Formula
Let's walk through the standard present-value formula Marcus's bond uses. This applies to fixed-rate coupon bonds on a coupon payment date.
Bond Price = ฮฃ [ C / (1 + r)^t ] + F / (1 + r)^n
Sum coupon payments t = 1 to n, then add discounted face value F.
- FFace value (par). The principal repaid at maturity.
- CCoupon payment per period. Annual coupon divided by payment frequency.
- rYield per period. Annual YTM divided by how many coupons per year.
- nTotal number of coupon periods left until maturity.
Marcus's calculation step by step
Coupon per period
$10,000 ร 4.75% รท 2
C = $237.50
Yield per period
6.25% รท 2
r = 3.125% (0.03125)
Number of periods
12 years ร 2 payments per year
n = 24
Discount each cash flow and sum
PV of 24 coupons + PV of $10,000 face
Bond Price = $8,746.77
Here's where it gets interesting: if Marcus's required yield dropped from 6.25% to 4.75% (matching the coupon), the bond price would land right at $10,000. Par value. Same bond, different market rate, totally different price.
Of course, you can skip all this counting and let the Bond Calculator do it instantly.
Where Bond Pricing Actually Gets Used
Marcus rebids after a rate hike
Two weeks after his first quote, the Fed hints at higher rates and the same bond's market price drops to $8,520. Marcus switches Solve For to Yield, enters the new price, and sees YTM jump to roughly 6.58%. He doesn't need to re-enter face value or coupon. He just updates the one number that moved.
Treasury ladder planning
Priya builds a five-rung Treasury ladder. She runs each maturity through the calculator at current YTM to compare which rung gives the best income per dollar invested.
What if you buy between coupon dates?
Consider Kevin, who settles a municipal bond on March 14 but the last coupon paid on March 1. The seller earned 13 days of interest that Kevin must reimburse at closing. Settlement Pricing mode shows clean price at $9,412.30, accrued interest at $16.88, and dirty price at $9,429.18. That dirty number is what actually leaves his account. And now he knows why the invoice doesn't match the screen quote.
Duration check before a rate decision
Before every central bank meeting, desk analysts scan modified duration to estimate how much bond prices might swing if yields move 0.25%. Our results panel shows Macaulay and modified duration alongside price. ๐
Clean Price vs Dirty Price: Where People Get It Wrong
Here's where most people get confused about bond pricing: they see a clean price of $9,412.30, submit that as their limit order, and then get filled at $9,429.18. The order looked right. The cash out the door was higher.
Accrued interest bridges that gap. On a $10,000 face bond with a $237.50 semiannual coupon, roughly 13 days of accrued interest might add $16.88 to the invoice. Small on one bond. On a $100,000 position, that's $168.80 you didn't budget for if you only priced the clean side.
See the difference? Clean price is what the market quotes. Dirty price is what you wire. Our calculator shows both so you can match your trade confirm to your model before settlement, not after.
That's why Settlement Pricing mode exists as a separate tab from Coupon Date mode. Use the right one for where you are in the trade lifecycle.
FAQs
How do you calculate a bond?
You discount every future coupon payment and the face value at maturity back to today using the yield to maturity. Here's the step-by-step: (1) Find the coupon per period by multiplying face value by the annual coupon rate and dividing by payment frequency. (2) Convert annual YTM to a per-period rate the same way. (3) Count how many payment periods remain. (4) Discount each coupon and the final face-value payment. (5) Add them up. That's your bond price. Our Coupon Date mode does all five steps in real time.
What is the formula for calculating bonds?
The core formula is: Bond Price = sum of [C / (1 + r)^t] for t = 1 to n, plus F / (1 + r)^n. C is the coupon per period, r is the yield per period, n is the number of periods left, and F is face value. It's the same present-value math you'd use in a [LINK: present value calculator], just repeated for every coupon date. If the bond trades between coupon dates, you also add accrued interest to get the dirty price.
What does a 5% bond yield mean?
It means your annualized return to maturity is about 5% if you buy at the current price and hold until the bond matures, assuming you reinvest coupons at the same rate. It doesn't automatically mean the bond pays a 5% coupon. A bond with a 3% coupon can have a 5% YTM if it's priced at a deep enough discount. Check both the coupon rate and the yield before you buy.
How much will a $10,000 bond be worth in 5 years?
If you hold a $10,000 face-value bond to maturity in 5 years, you receive $10,000 in principal back, plus whatever coupons paid along the way. The market price today is a different question. For example, Marcus's $10,000 bond with a 4.75% coupon and 12 years left prices at about $8,747 when investors want 6.25%. In 5 years, with 7 years remaining, the price will depend on whatever yield the market demands then. Run the calculator with 7 years and your best yield guess to estimate it.
How much do you have to pay on a $100,000 bond?
You rarely pay exactly $100,000 for a $100,000 face-value bond. You pay the dirty price, which is the clean price plus accrued interest. Scale Marcus's example: a bond priced at $8,746.77 per $10,000 face works out to roughly $87,467.70 for a $100,000 position (before accrued interest). If the bond trades at a premium, you'd pay more than face. Enter $100,000 as face value, your coupon, yield, and years in the calculator to get the exact invoice amount.
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