Financial

COUPDAYS Function in Excel

Returns the number of days in the coupon period that contains the settlement date.

Syntax

  • =COUPDAYS(settlement, maturity, frequency, [basis])

Arguments

  • settlement (required): Settlement date
  • maturity (required): Maturity date
  • frequency (required): Payments per year (1, 2, or 4)
  • basis (optional): Day count basis

Examples

  • =COUPDAYS("1/25/2024", "11/15/2027", 2) - Days in coupon period - Result: 181

COUPDAYS modeling tips

  • Align rate and period units (annual rate ÷ 12 for monthly models).
  • Use consistent cash-flow signs (outflows negative, inflows positive).
  • Hub: [Financial functions guide](/guides/excel-financial-functions-guide/).

Common errors

  • #NUM! if dates invalid

Use cases

  • Bond pricing
  • Interest calculation
  • Fixed income

Frequently asked questions

  • What is the COUPDAYS function in Excel? COUPDAYS returns the number of days in the coupon period that contains the settlement date. The syntax is =COUPDAYS(settlement, maturity, frequency, [basis]). Typical use cases include bond pricing, interest calculation, fixed income.
  • How do I use the COUPDAYS function? To use COUPDAYS, type =COUPDAYS( in a cell and provide the required arguments. Excel will show you the syntax and parameter hints as you type. Make sure to close the parentheses and press Enter to execute the function.
  • Why is COUPDAYS not working in my Excel? Common issues with COUPDAYS include #NUM! if dates invalid. Start by checking the syntax =COUPDAYS(settlement, maturity, frequency, [basis]), then verify each referenced cell or range.

Editorial review

  • Reviewed by Excel.Directory Editorial Team. Updated May 2026.