COUPDAYS Function in Excel: Days in the Current Coupon Period

COUPDAYS Function in Excel: Days in the Current Coupon Period 1
⏱ 1 min readUpdated 5 October 2026

FinanceLevel: ExpertAvailable in: Excel 2007+

In this article
  1. Syntax
  2. Examples
  3. Example 1
  4. COUPDAYS in practice
  5. Where you will use it
  6. Worked example
  7. Mistakes people make
  8. Related functions

COUPDAYS returns the number of days in the coupon period that contains settlement. Used for bond pricing and accrued interest on half-yearly coupons.

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Syntax

=COUPDAYS(settlement, maturity, frequency, [basis])
Argument What it means
settlement Purchase date
maturity Maturity date
frequency 1, 2 or 4 coupons a year
basis Day count

Examples

Example 1

=COUPDAYS(A2,B2,2,1)

Result: 181. See the worked example table below for more cases.

COUPDAYS in practice

Where you will use it

  • Accrued interest when buying a bond between coupons
  • Cash-flow schedules
  • Treasury desk reports

Worked example

SettlementMaturityFormulaResult
05-10-202631-03-2031=COUPDAYS(A2,B2,2,1)181
10-01-202631-12-2030=COUPDAYS(A3,B3,2,1)181
15-06-202615-06-2028=COUPDAYS(A4,B4,2,1)183

Results calculated in Excel.

Mistakes people make

MistakeWhat to do instead
Settlement after maturity#NUM!
Wrong frequencyUse the bond's real coupon frequency

COUPNCD · COUPNUM · ACCRINT

📚 Part of the free Excel course: Beginner → Expert · Try it in the Formula Lab or ask the AI Helper.

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