Six inputs. Zero ambiguity. Instant settlement-grade output. Free, no signup, designed for fixed income professionals, operations teams, students and individual bond investors.
Most online accrued interest calculators ask you to enter the last coupon date as a separate input – forcing you to work it out manually before you can use the tool. This is unnecessary and a common source of error.
This calculator derives the last coupon date from the maturity date and coupon frequency automatically. The schedule reconstruction is internal:
You enter the inputs you actually have from the bond’s term sheet — coupon rate, nominal, maturity, frequency, clean price, settlement date. The calculator handles the schedule mechanics.
The market price quoted on Bloomberg, broker screens and price feeds – the price excluding accrued interest. Enter as a percentage of nominal: 98.50 means the bond trades at 98.5% of face value.
The clean price moves with market conditions – yield changes, spread changes, supply and demand. It does not change just because a day passes. This is precisely why bond markets quote clean prices: it isolates market valuation from the calendar.
The date cash and securities change hands – typically T+1 for US Treasuries (since May 2024) and T+2 for corporate bonds in most markets. This is the date used for the accrual calculation, not the trade date.
For a bond already in your portfolio, enter today’s date. For a planned purchase, enter the actual settlement date your broker quotes — not when you place the order.
The annual interest rate as a percentage of nominal value. A 4.5% coupon on $1,000 nominal pays $45 per year, distributed across coupon dates according to the frequency.
Coupon rate is fixed at issuance and does not change for a standard fixed-rate bond. Do not confuse it with yield to maturity – the two converge only when the bond trades at par.
The face value the issuer repays at maturity. Standard nominals are $1,000 in the US, £100 in the UK, €1,000 in most of Europe. The calculator outputs accrued interest in the same currency units as the nominal you enter.
The date the issuer repays the nominal value. Combined with coupon frequency, this fully specifies the coupon schedule. A semi-annual bond maturing 15 October 2031 pays on 15 April and 15 October each year. A quarterly bond maturing 30 June 2030 pays on 30 March, 30 June, 30 September and 30 December.
Annual – most European corporate bonds, some sovereigns
Semi-annual – US Treasuries, US corporate bonds, UK gilts, most international markets
Quarterly – some structured products and FRNs
Reconstructed from maturity date and frequency. The last coupon before settlement anchors the accrual; the next coupon defines the period denominator.
The numerator and denominator of the accrual fraction. For standard semi-annual bonds, periods are typically 181, 182, 183 or 184 days depending on which calendar months are involved.
Accrued Interest = (Coupon Rate / Frequency) × Nominal × (Days Since Last Coupon / Days in Period)
Dirty Price = Clean Price + Accrued Interest per 100 Nominal
Settlement Amount = Dirty Price × Nominal / 100
The 4.0% February 2034 Treasury note. Settlement on 27 April 2026:
| Input | Value |
|---|---|
| Clean price | 97.25 |
| Settlement date | 27 April 2026 |
| Coupon rate | 4.0% |
| Nominal | $10,000 |
| Maturity date | 15 February 2034 |
| Coupon frequency | Semi-annual |
Maturity 15 February 2034, semi-annual → coupons on 15 February and 15 August each year.
Last coupon before 27 April 2026: 15 February 2026 Next coupon: 15 August 2026
Days since 15 February 2026 to 27 April 2026:
Feb (15→28): 13 days
Mar: 31 days
Apr (1→27): 27 days
Total: 71 days
Days in period (15 February to 15 August 2026): 13 + 31 + 30 + 31 + 30 + 31 + 15 = 181 days
Semi-annual coupon = $10,000 × 4.0% / 2 = $200
Accrued Interest = $200 × (71 / 181) = $78.45
Per 100 nominal: 78.45 / 100 = 0.7845
[H3] Step 4 — Dirty price and settlement
Dirty Price = 97.25 + 0.7845 = 98.0345
Settlement Amount = $10,000 × 98.0345 / 100 = $9,803.45
The buyer pays $9,803.45 at settlement: $9,725.00 for the bond’s market value plus $78.45 compensating the seller for 71 days of accrued coupon income.
The settlement amount is the cash you must have available on T+1 or T+2. The accrued interest portion is not “extra cost” – it is prepaid income. You will recover it when the next coupon arrives.
The settlement amount is the cash you receive. The accrued interest portion is taxable as interest income (not capital gain) in most jurisdictions, regardless of how long you held the bond.
Use the dirty price for true position economics. Clean prices understate position value by the accrued amount. Risk systems that use clean prices will systematically misstate exposure between coupon dates.
Both should use dirty prices. Using clean prices introduces errors of 5–15 basis points in YTM and meaningful weight distortion in duration – small but material in precision work.
Three common reasons. First, day-count convention – Bloomberg defaults to the convention specified in the bond’s terms, which may be 30/360 for US corporate bonds rather than Actual/Actual. Second, settlement date – Bloomberg adds the settlement convention (T+1 or T+2) to the trade date automatically; if you entered the trade date here as settlement, you are missing 1-2 days. Third, ex-dividend period – for UK gilts and some other markets within the ex-dividend window, accrued interest goes negative. Confirm all three before assuming a calculation error.
The May 2024 transition from T+2 to T+1 in US securities shortened the gap between trade date and settlement date. If you previously entered today’s date for an immediate trade, the accrued interest would have included two extra days under T+2. Under T+1, it includes only one extra day. The mechanics are unchanged – only the gap between trade and settlement. For modelling, always use the actual settlement date the trade will settle on, not the trade date.
Custodians and dealers occasionally use slightly different day-count rounding or 30/360 variants (30E/360 vs 30/360 ISDA vs 30/360 Bond Basis). On a single bond these differences produce $0.50–$5.00 discrepancies that aggregate to material amounts across a portfolio. The reconciliation difference is almost never an error in any single calculation — it is a convention mismatch between systems. Check the bond’s prospectus for the contractually specified convention and configure your system to match.
A bond issued mid-period has a “long first coupon” or “short first coupon” – a non-standard period before the first regular coupon. The calculator handles regular periods automatically. For an odd first coupon, accrued interest in that initial period requires the actual issue date, not just the maturity date and frequency. If you are settling a bond in its first coupon period, verify the issue date against the bond’s prospectus and use the actual issue date as the “last coupon date” for that period.
Partially. For a floating-rate note (FRN), the coupon rate changes at each reset date based on a reference rate. To use this calculator on an FRN, enter the current coupon rate (the rate set at the most recent reset). The accrued interest calculation through the current period will be accurate. At the next reset, the coupon rate will change and you would need to update the input. For most FRN analysis, accrued interest between resets is small (typically 1-3 months of period) and tracking is operationally simple.
A defaulted or distressed bond trades “flat” – the quoted price is the dirty price directly, with no accrued interest component because future coupon payments are uncertain. For flat-trading bonds, do not use this calculator’s accrued output. The clean price you would enter is also misleading, because flat-traded bonds are not really priced on the clean/accrued framework. Treat the quoted price as the full settlement value.
The calculator computes accrued interest as a positive number based on days elapsed since the last coupon. For UK gilts and other markets with ex-dividend periods, trades settling within the ex-dividend window technically produce negative accrued interest (the seller pays the buyer because the buyer will not receive the upcoming coupon). For ex-dividend transactions in these markets, use the calculator’s output as the gross accrual and apply the negative sign manually. Most US users will never encounter this.
For the four day-count conventions and which markets use each, ex-dividend mechanics in detail, settlement convention impact on accrued, accrued at default and flat trading, repo and swap implications, tax treatment with the US accrued interest deduction election, and IFRS 9 / GAAP financial reporting treatment:
👉 Bond Accrued Interest & Dirty Price — Complete Professional Guide
This calculator’s outputs feed directly into other tools on this site. Use them in sequence for complete bond analysis:
For accurate Macaulay and Modified Duration
Calculate Bond Yield that pays coupon periodically
For option-embedded bond risk analysis