RRI Function (OpenOffice Calc)

• Introduced: First release not established; documented by OpenOffice.org 3.3.
• Supported in: Apache OpenOffice 4.1.16; this is a verified release, not a final supported version.
• Scope: Desktop Calc, English function names and semicolon-separated formulas.
• Checked: October 14, 2026. Eight ordinary reference formulas were recalculated from generated ODF in 4.1.16 on Linux x86-64, Build 9816. Source and independent mathematics were also checked.

RRI calculates the constant per-period compound rate (FutureValue/PresentValue)^(1/Periods)−1. It summarizes growth between two amounts when there are no intermediate cash flows. It does not measure a money-weighted return for deposits or withdrawals between those dates. Release implementation.

=RRI(Periods; PresentValue; FutureValue)

All three arguments are required. Periods is the elapsed period count; PresentValue and FutureValue are the starting and ending amounts in the same unit. For the ordinary growth interpretation, use positive Periods and PresentValue with a nonnegative FutureValue. Here the two values are same-sign magnitudes, unlike opposite signed cash flows in a PV/FV annuity equation.

The native column contains saved 4.1.16 results; the independent column uses high-precision mathematical calculations. Values are displayed to twelve decimal places, so harmless final-place differences remain visible. Rate decimals such as 0.05 represent 5%, not 0.05%.

The displayed English name is RRI. The generated ODF uses ZGZ, its opcode-backed storage name, and the saved file retained that exact operation. ODF-name registration and English-name registration establish the mapping. These are ODF-format execution results, not manual English-name entry.

A hypothetical amount doubling from 1000 to 2000 over ten years has =RRI(10;1000;2000) of approximately 0.071773462536, or 7.1773462536% per year. This equivalent constant rate describes the two endpoints; actual yearly returns may have varied. It does not forecast the next year.

For 100 declining to 81 over two periods, RRI returns −0.1, meaning a constant 10% loss per period reproduces the endpoints: 100×0.9²=81. A decline is represented by the endpoint ratio below one, not by arbitrarily negating one amount.

Check a valid result r by reconstructing FutureValue=PresentValue×(1+r)^Periods. A zero growth case with equal positive endpoints gives r=0. The executed zero-final-value example gives −1, the complete-loss boundary for a positive elapsed count.

The unit comes from Periods. If twelve equal months take 1000 to 1200, RRI(12;1000;1200) is a monthly equivalent rate. Its effective annual factor is (1+monthlyRate)^12=1.2. Do not label the monthly decimal as an annual percentage.

A fractional elapsed period count is an algebraic duration, not evidence of an actual dated investment calendar. Use a method designed for dated cash flows when contributions, withdrawals or irregular dates matter.

The source directly evaluates a power of the endpoint ratio. Zero starting value, zero periods or a negative ratio can leave the real mathematical domain. Some signed or negative-period combinations may still produce finite arithmetic values without representing the stated growth model. Validate the assumptions rather than accepting every numeric result.

power, XIRR, RATE.

• Function-specific release entry

The generated ODF input produced the informational load warning “Not all attributes could be read.” After it was acknowledged, the sheet was hard-recalculated and saved separately. All eight ordinary function identities and results were reconciled; a stale SUM cache changed from 999999 to 3 and an uncached SUM returned 7. This establishes the stated formula examples, not every workbook style or every invalid input. The original XLSX was not executed. Other explanatory calculations are independent mathematical checks; this guide does not claim a fully executed amortization schedule, other releases or all boundary cases.