MIRR Function in SoftMaker PlanMaker 2026: Syntax, Worked Examples & Troubleshooting

• Introduced: Documented in the PlanMaker 2016 manual; the original introduction release and date remain unknown.
• Availability: Documented in the 2026 English reference; no final supported-version endpoint is established.
• Scope: Versioned documentation does not establish identical behavior across desktop, mobile or localized builds.
• Checked: October 14, 2026, against the official MIRR reference, with independent cash-flow calculations. No native PlanMaker test.

=MIRR(Values, FinanceRate, ReinvestRate)

All three arguments are required; the 2026 MIRR reference documents no optional defaults.

Payments are negative, receipts positive, and at least one of each is required. Amounts can vary while time intervals remain equal. The rate units must match those intervals. Use your editor’s formula-entry separators; the English examples here use commas.

IRR solves a different equation and takes no separate financing/reinvestment rates. Neither function accepts individual dates; XIRR provides a separate date-aware interface.

Use a blank worksheet. Enter the following four amounts in A2:A5; column B can hold the timing labels:

Put 8% in E2 and 6% in E3. In G2 enter =MIRR(A2:A5,$E$2,$E$3) and apply Percentage formatting. Expect approximately 13.503742%, or 0.1350374211 before formatting. Four entries span three annual intervals.

In G4 enter =A3*(1+$E$3)^2+A4*(1+$E$3)+A5. It compounds positive receipts to the end of year 3: expect 14,622.80. The first receipt grows for two years, the second for one, and the final receipt has no remaining reinvestment interval.

In G5 enter =-A2, the positive magnitude of the initial investment: 10,000. In G6 enter =(G4/G5)^(1/3)-1; expect the same 13.503742% as G2. In G7 enter =G6-G2; expect a small numerical residual near zero.

The only negative cash flow here occurs at time zero, so FinanceRate does not change its present value. Changing E2 alone therefore leaves this particular model’s MIRR unchanged. That is a property of this dataset, not a reason to omit the required argument.

Keep A:B intact. Put -10000, 3000, -2000, 9000 in C2:C5, with the same four annual times. In H2 enter =MIRR(C2:C5,$E$2,$E$3). Expect approximately 1.833143% per year.

Construct a second check:

The negative 2,000 occurs two intervals after time zero, so it is discounted at FinanceRate before being combined with the initial outlay. Do not subtract it from the positive terminal receipts: financing and reinvestment use different rates and different time directions in this model.

In J2:L2 enter Finance, Reinvest, MIRR. Enter these two rate columns in J3:K5, then place =MIRR($C$2:$C$5,J3,K3) in L3 and fill through L5:

The first comparison changes what early positive receipts grow into. The last comparison changes the present-value treatment of the later negative amount. These are model sensitivities, not evidence that a higher financing cost makes the underlying project economically better.

If rows instead represent months, supply monthly financing and reinvestment rates, and interpret the output per month. A nominal annual rate quoted with monthly compounding is divided by 12; an effective annual rate converts by (1+annual)^(1/12)-1. Do not mix those conventions.

For example, a 1% monthly modified return has effective annual equivalent (1+1%)^12-1, approximately 12.682503%. Multiplying by 12 gives a different nominalized 12%. Annualization does not make irregular transaction dates suitable for MIRR.

• One sign only: SoftMaker requires at least one negative payment and one positive receipt. The exact function-specific error for every invalid stream is not specified by its short entry.
• Wrong exponent: four cash-flow entries represent three intervals after the initial amount. Count intervals rather than rows in the independent check.
• Missing period: preserve a numeric zero for a known no-cash-flow interval. Removing its row shifts later transactions earlier.
• Rates reversed: FinanceRate applies to negative cash flows; ReinvestRate applies to positive cash flows. Their positions are not interchangeable.
• Text, blanks or logical values: the cited page does not establish all coercion rules. Keep the worked series numeric instead of importing another product’s blank-handling behavior.
• Unexpected result after import: confirm order, signs, rate units, number formats and recalculation in the receiving app.

NPV evaluates regular cash flows at a supplied discount rate and is useful alongside return calculations. MIRR does not choose realistic funding assumptions, include missing fees, or determine whether a project is appropriate for an investor.