CUMPRINC in Collabora Office: Total Principal Repaid Across Selected Periods

The dedicated Collabora page’s opening sentence says “cumulative interest,” but its CUMPRINC name and worked example describe payoff amounts. An independent principal-amortization calculation reproduces the example’s −3669.74; the interest total for that window is instead approximately −406.71.

This guide preserves that source discrepancy rather than silently treating the introduction as a second contract. The calculations below follow the principal/payoff meaning supported by the worked example, with no native Collabora execution claimed.

=CUMPRINC(Rate; NPer; PV; S; E; Type)

All six arguments are required. Rate is the periodic interest rate. NPer is the total number of periods; the help explicitly permits noninteger NPer, though these examples use whole periods. PV is present value. S and E are the first and last periods of the cumulative window. Type gives payment timing.

The source example uses Type 0 for end-of-period payments; the companion CUMIPMT example uses Type 1 for beginning-of-period payments. There is no omitted timing default in this syntax.

Enter the rate formula =5.5%/12 in B2, then NPer 36, PV 15000, S 10, E 18, and Type 0 in B3:B7. In B9 use =CUMPRINC(B2;B3;B4;B5;B6;B7).

An independent amortization schedule gives approximately −3669.735515698, consistent with the vendor’s rounded −3669.74. The window contains nine periods, 10 through 18 inclusive.

The negative sign is the outward-payment convention in the source’s borrower-style example. Its magnitude is principal repaid. Do not change the sign without also explaining which cash-flow perspective the report uses.

The independent regular payment magnitude is approximately 452.938527065. Nine payments total approximately 4076.446743582. For this window, the independent interest magnitude is approximately 406.711227884.

Subtracting interest from the payment total gives principal 3669.735515698. This arithmetic provides a separate check on the function’s payoff example and distinguishes it from the page’s misleading introductory word “interest.”

PMT is a related guide for the whole payment; PPMT concerns a single period’s principal. Compare only formulas using the same rate, timing, and total-period assumptions.

For present value 1200, monthly rate 1%, total periods 12, window 1 through 3, and Type 0, the independent cumulative principal paid is approximately 286.703657489.

The remaining balance after those three payments is 1200−286.703657489≈913.296342511. The cumulative interest magnitude is approximately 33.151981753, and total payments are approximately 319.855639242.

Thus =CUMPRINC(1%;12;1200;1;3;0) has independent expectation −286.703657489 in the source sign convention. This is a hypothetical mathematical schedule, not an actual loan account or native test.

For a fixed model, the independently calculated principal sums for periods 1–3 and 4–6 add to the sum for periods 1–6. The two windows must not overlap; using 1–3 and 3–6 counts period 3 twice.

SUM can combine separately computed windows. Retain full precision until the reporting stage because adding rounded subtotals may differ from rounding the complete unrounded total.

Check periodic rate units, positive total duration, the period window, and payment timing. The dedicated source does not comprehensively state exact native errors for zero rates, fractional windows, invalid indices, or text coercion. Its allowance for noninteger NPer is not a verification of every fractional case.

The independent model uses constant rates and regular payments. It does not include changing rates, fees, skipped payments, or prepayments. Resolve the source wording discrepancy and validate your actual Collabora version before relying on a high-stakes schedule.

The exact function is documented in Collabora Office 26.04 desktop help, retrieved and reviewed on October 17, 2026. This establishes a documentation scope, not the first release that introduced the function or the last version in which it works; those versions and any retirement date remain unestablished. Collabora Online and mobile support are not inferred from desktop help, nor is behavior in another spreadsheet product.

The examples are documentation-based expectations with independent calculations. They have not been executed in Collabora Office. No application screenshot or native error/coercion certification is implied. Formulas use English function names and semicolon argument separators.

• Collabora Office 26.04: CUMPRINC (checked October 17, 2026).
• Editorial testing standards.