CUMIPMT_ADD Function (LibreOffice Calc)

• Introduced: First release not established; documented by LibreOffice 3.3.
• Supported in: Documented in LibreOffice 26.8 Help and registered in 26.8.1.1. No retirement is established.
• Scope: Desktop Calc, English compatibility function name and semicolon-separated formulas. A suffix does not by itself mean deprecated or retired.
• Checked: October 14, 2026. Eight reference calculations and the function-specific documentation were checked. Complete financial wrapper guards were not inspected. No native execution is claimed.

CUMIPMT_ADD is the Analysis add-in’s cumulative-interest function. It adds interest portions for an inclusive interval of a level-payment loan. The suffix distinguishes it from core CUMIPMT; LibreOffice documents the suffixed compatibility variant separately from the standards-oriented unsuffixed function. Function-specific Help.

LibreOffice’s documentation describes _ADD names as compatibility variants associated with Excel 2003 behavior and recommends the unsuffixed functions for standards-oriented results. Keep the exact original function name when evaluating an imported workbook.

=CUMIPMT_ADD(Rate;Nper;PV;StartPeriod;EndPeriod;Type)

• Rate: interest rate per payment period; the references use positive rates.
• Nper: total count of equal payment periods.
• PV: positive initial loan amount in these examples.
• StartPeriod, EndPeriod: inclusive payment numbers; use integers with 1≤StartPeriod≤EndPeriod≤Nper.
• Type: documented timing flag, 0 for end-of-period payments or 1 for beginning-of-period payments.

All six arguments are required. Keep the rate and total count in the same period unit. These examples deliberately use ordinary integer counts and valid intervals; they do not establish every argument-conversion or validation branch.

These references use a constant-payment amortization model. Noninteger values are displayed to twelve decimal places; intermediate calculations retain greater precision.

For a 1000 loan at 1% per period with twelve end-of-period payments, the independent reference calculation gives approximately −66.185464140100 over all twelve payments. Periods 1 through 3 contain approximately −27.626651460782 of interest; periods 4 through 6 contain approximately −20.387145189468.

A positive principal is an inflow to the borrower, so repayments are negative. Negate the returned amount only when a report deliberately presents interest cost as positive. Do not remove the sign before combining it with other signed cash flows.

The independent payment is -1000*.01/(1-(1.01)^(-12)), approximately −88.848788678342. Its first interest portion is −10. Repeatedly update the outstanding balance by the principal portion and accumulate the interest to reproduce the displayed result.

Beginning-of-period timing changes the payment and makes the first interest portion zero. Its total interest here is approximately −55.629172415941. The corresponding principal total is −1000, so interest plus principal equals twelve signed payments. These are equal-period calculations, not an irregular-date interest accrual.

Use a positive rate and principal, positive integer total count, an inclusive interval within that count and Type 0 or 1 for the ordinary model shown. These are explicit assumptions for the reference calculations, not a claim that every other input produces a particular LibreOffice error.

The current financial worksheet wrapper was not included in the inspected source set. Its exact coercion and validation branches therefore remain unverified here. Fractional counts, other timing flags, zero-rate behavior, blank cells, text and extreme values were not executed. Do not copy Apache OpenOffice or core-function edge behavior onto this compatibility name without separate evidence.

CUMIPMT, IPMT, PMT.

• Function-specific Help and compatibility note
• Versioned Analysis add-in registration

The references establish the documented ordinary model. Native execution, exceptional-input behavior and cross-product equivalence remain unverified.