COUPNUM Function (LibreOffice Calc)

Financial Advanced LibreOffice Calc Introduced in LibreOffice 3.0
finance bonds coupons valuation fixed-income cashflows

The COUPNUM function returns the number of coupon periods between the settlement date and the maturity date. It is essential for bond valuation, yield calculations, and financial modeling involving coupon schedules.

Compatibility

What the COUPNUM Function Does

  • Returns the count of coupon periods between settlement and maturity
  • Uses coupon frequency (annual, semiannual, quarterly)
  • Supports multiple day‑count basis systems
  • Works with real dates, serial numbers, and DATEVALUE

It is designed to be precise, finance‑grade, and Excel‑compatible.

Syntax

COUPNUM(settlement; maturity; frequency; [basis])

Arguments

  • settlement:
    The date the security is traded to the buyer.

  • maturity:
    The date the security matures.

  • frequency:
    Number of coupon payments per year:

    • 1 = annual
    • 2 = semiannual
    • 4 = quarterly
  • basis (optional):
    Day-count convention:

basis Day-count convention
0 US 30/360
1 Actual/Actual
2 Actual/360
3 Actual/365
4 European 30/360

Basic Examples

Number of coupon periods (semiannual)

=COUPNUM("2024-03-15"; "2026-03-15"; 2)

Using Actual/Actual

=COUPNUM(A1; A2; 2; 1)

Using text dates

=COUPNUM(DATEVALUE(A1); DATEVALUE(A2); 2)

Advanced Examples

Quarterly coupon periods

=COUPNUM("2024-02-10"; "2025-02-10"; 4)

From imported CSV timestamps

=COUPNUM(DATEVALUE(LEFT(A1;10)); DATEVALUE(LEFT(A2;10)); Frequency)

From Excel serial dates stored as text

=COUPNUM(DATE(1899;12;30)+VALUE(A1); DATE(1899;12;30)+VALUE(A2); Frequency)

Combine with COUPPCD and COUPNCD to build a full coupon schedule

=COUPNUM(A1; A2; Freq)

Determine if a bond has only one coupon remaining

=COUPNUM(A1; A2; Freq) = 1

Use in yield calculations

=YIELD(Settlement; Maturity; Rate; Price; Redemption; Freq; Basis)

Use in price calculations

=PRICE(Settlement; Maturity; Rate; Yield; Redemption; Freq; Basis)

Edge Cases and Behavior Details

COUPNUM returns an integer

Accepts:

  • Real dates
  • Serial numbers
  • DATEVALUE outputs

Invalid text → Err:502

Behavior details

  • Settlement < Maturity must hold
  • Frequency must be 1, 2, or 4
  • Basis must be 0–4
  • Coupon schedule is calculated backward from maturity
  • Time components ignored

COUPNUM of an error → error propagates

Common Errors and Fixes

Err:502 — Invalid argument

Cause:

  • Dates not recognized
  • Frequency not 1, 2, or 4
  • Basis outside 0–4

Fix:

  • Wrap dates with DATEVALUE
  • Validate frequency and basis

Err:504 — Invalid date sequence

Cause:

  • Settlement after maturity

Fix:

  • Correct date order

Unexpected coupon count

Cause:

  • Wrong frequency
  • Incorrect maturity date
  • Wrong day-count basis

Fix:

  • Verify coupon schedule
  • Confirm basis selection

Best Practices

  • Use Actual/Actual (basis 1) for government bonds
  • Use 30/360 for corporate bonds
  • Normalize text dates with DATEVALUE
  • Validate coupon frequency carefully
  • Use COUPNUM with COUPDAYS, COUPDAYSNC, COUPPCD, and COUPNCD for full coupon modeling
COUPNUM is your coupon‑count engine — essential for price, yield, accrued interest, and any professional fixed‑income model.

Related Patterns and Alternatives

  • Use COUPDAYS for total days in coupon period
  • Use COUPDAYSNC for days to next coupon
  • Use COUPPCD for previous coupon date
  • Use COUPNCD for next coupon date
  • Use ACCRINT for accrued interest
  • Use PRICE and YIELD for bond valuation

By mastering COUPNUM and its companion functions, you can build powerful, accurate, and fully professional fixed‑income models in LibreOffice Calc.

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