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Bond Price Calculator

Calculate bond prices from yield, coupon rate, face value, and maturity with duration and convexity analysis.

Tested tool guide Tested browser tools Checked August 15, 2026

What Bond Price Calculator does, with a checked example

Enter a bond's face value, coupon rate, yield to maturity, years to maturity, and payment frequency, and the calculator discounts each coupon payment plus the final redemption back to today at the periodic yield, then reports Macaulay duration, modified duration, and convexity alongside the price. The result that surprises people most: price and yield move in opposite directions, so raising the yield input lowers the computed price, and any bond whose coupon rate sits below the entered yield will always price under face value, never at or above it.

Worked example

A concrete input and expected output from the current implementation.

Input

Face value $1,000; annual coupon rate 5%, paid semiannually ($25 every 6 months); yield to maturity 6% annual, compounded semiannually; 2 years to maturity (4 periods).

Expected output

Price approximately $981.41 (a discount to face value).

Each $25 coupon and the final $1,000 redemption are discounted at 3% per semiannual period across 4 periods; the discounted cash flows sum to about $981.41. Because the 6% yield exceeds the 5% coupon rate, the bond prices below its $1,000 face value.

How the result is produced

1

Cash flow discounting

The bond is split into its periodic coupon payments (face value times coupon rate, divided by payments per year) plus a single final face-value redemption. Each cash flow is discounted back to today using the periodic yield (annual yield to maturity divided by the compounding frequency) raised to the power of the number of periods remaining, and the discounted amounts are summed to get the price.

2

Duration and convexity

Macaulay duration is the present-value-weighted average time to each cash flow; modified duration divides that by (1 + periodic yield) to approximate the percent price change for a 1 percentage-point yield move. Convexity measures the curvature that a linear duration estimate misses, refining the price-change approximation for larger yield swings.

Good uses

  • Estimating what a bond is worth today given a quoted yield to maturity, before deciding whether to buy at the market price.
  • Checking how much a bond's price would move for a given change in interest rates, using the reported duration and convexity.
  • Comparing a fundamentals-based price against a broker's quoted price to see whether the quote looks rich or cheap relative to the stated yield.

Limits and checks

  • The price assumes one flat yield applied to every cash flow, not a real term structure with different rates by maturity, so it can diverge from market price when the yield curve is steeply sloped.
  • Duration and modified duration approximate price sensitivity for small, parallel yield shifts; for a large move of several percentage points, the duration-and-convexity estimate will diverge from what the full discounting formula produces.
  • The formula prices as of a coupon date with a whole number of periods remaining, which is a clean price; it does not automatically reflect accrued interest for a purchase settling between coupon dates unless that is added separately.

Common questions

Why did the price come out below the $1,000 face value even though the bond pays a coupon?

Because the yield to maturity entered is higher than the coupon rate. When yield exceeds the coupon rate the bond prices below face value (a discount); when yield is lower than the coupon it prices above face value (a premium); the two match only when coupon rate equals yield.

Does the output include accrued interest for a bond bought between coupon dates?

Not clearly - the underlying formula prices as of a coupon date with a whole number of periods left, which is a clean price. If you're checking this against a broker's dirty-price quote for a mid-period settlement, verify separately whether accrued interest needs to be added on top.

References and verification

The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.

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