Calculator inputs
Formula used
Coupon Payment = Face Value × Annual Coupon Rate ÷ Payment Frequency
Accrued Interest = Coupon Payment × (Accrued Days ÷ Days in Coupon Period)
Accrued Interest per 100 = Accrued Interest ÷ (Face Value ÷ 100)
Dirty Price per 100 = Clean Price per 100 + Accrued Interest per 100
This page supports Actual/Actual, 30/360 US, Actual/360, and Actual/365 methods. The selected convention changes the accrued-day fraction and can materially change settlement totals.
How to use this calculator
- Enter the bond’s total face value and the par value per bond.
- Add the annual coupon rate and choose the payment frequency.
- Enter the last coupon date and the settlement date.
- Enter the next coupon date, or leave it blank for auto-generation.
- Select the day-count basis used for the bond market convention.
- Optionally add the clean price per 100 to estimate dirty price and invoice amount.
- Press calculate to show results above the form and below the header.
- Use the export buttons to save a CSV summary or PDF copy.
Example data table
| Input or Output | Example value |
|---|---|
| Total face value | $100,000.00 |
| Par value per bond | $100.00 |
| Coupon rate | 8.00% |
| Payment frequency | Semiannual |
| Last coupon date | 2026-01-01 |
| Settlement date | 2026-03-16 |
| Next coupon date | 2026-07-01 |
| Day-count basis | Actual/Actual |
| Clean price per 100 | 101.2500 |
| Accrued days | 74 |
| Days in coupon period | 181 |
| Accrued interest | $1,635.36 |
| Accrued interest per 100 face | 1.6354 |
| Dirty price per 100 | 102.8854 |
| Total invoice amount | $102,885.36 |
Answers to common bond questions
What is a bond's accrued interest?
A bond’s accrued interest is the coupon interest earned from the last coupon date up to the settlement date. Buyers usually reimburse sellers for that earned portion at settlement.
How to find accrued interest on a bond
First calculate the coupon payment for one period. Then multiply it by accrued days divided by total days in the coupon period, using the bond’s stated day-count convention.
garfunkel company issued $100000 of 12% 10-year bonds dated january 1 at par plus accrued interest
If the bonds sell between coupon dates, accrued interest equals $100,000 × 12% ÷ payment frequency × accrued days ÷ period days. “At par plus accrued interest” means the buyer pays face value plus earned coupon interest.
FAQs
1. What is the difference between coupon payment and accrued interest?
Coupon payment is the full interest paid on a scheduled coupon date. Accrued interest is only the earned fraction between the last coupon date and settlement.
2. Why is the dirty price higher than the clean price?
Dirty price includes accrued interest. Clean price excludes it. On most settlement dates between coupon payments, dirty price is higher because the seller already earned part of the next coupon.
3. Which day-count basis should I choose?
Use the basis specified in the bond terms or the market convention. Corporate, municipal, and government issues may follow different standards, so matching the security’s rule matters.
4. Can settlement occur on a coupon date?
Yes. If settlement occurs exactly on the coupon date, accrued interest is usually zero for the new period because the prior coupon has just been paid.
5. Does payment frequency affect accrued interest?
Yes. Frequency changes the coupon amount per period and the time length of each coupon interval. That changes the proportional interest earned by settlement.
6. Can this calculator handle a zero-coupon bond?
Yes, if the coupon rate is entered as zero. Accrued interest becomes zero because no periodic coupon is being earned between settlement dates.
7. Why does the total invoice differ from the quoted market price?
Market quotes often show clean price only. Settlement usually uses dirty price, which adds accrued interest. That makes the invoice higher than the quoted clean price.
8. Is this calculator useful for corporate, treasury, and municipal bonds?
It is useful for many fixed-income estimates. Still, always confirm coupon schedule, ex-interest rules, and day-count convention against the actual bond documentation.