EFFECTIVE 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 arithmetic were checked.

EFFECTIVE returns the effective annual rate produced by equally spaced periodic compounding of a nominal annual rate. It uses (1+NominalRate/Periods)^Periods−1 after flooring the period count. The English OpenOffice worksheet name is EFFECTIVE; its registered ODF storage name is EFFECT. Release implementation.

EFFECTIVE(NominalRate;Periods)

• NominalRate: required positive annual nominal rate as a decimal, for example 0.12 for 12%.
• Periods: required count at least 1. The implementation floors it before calculation. Use a whole count intentionally.
• Both arguments are required. The supported domain does not include a zero or negative nominal rate in this release.

The native column contains saved 4.1.16 results; independent references use high-precision arithmetic and the stated source rules. Values are shown to twelve decimal places where needed.

The generated ODF stores EFFECT, while the English worksheet name is EFFECTIVE. The ODF name and English name share SC_OPCODE_EFFEKTIV. This verifies the mapped ODF operation rather than manual English-name entry.

=EFFECTIVE(0.12;12) gives approximately 0.126825030132, or 12.6825030132%. The monthly periodic rate is 0.12/12=0.01, and twelve factors of 1.01 give an annual accumulation factor of about 1.126825030132.

With a nominal rate of 0.10 compounded twice annually, the result is 1.05²−1=0.1025, or 10.25%. Compare rates only when their periods and conventions are aligned; the function does not incorporate fees, irregular timing or taxes.

For a positive nominal rate, one compounding period gives the same effective rate. Increasing the number of equal periods increases the effective rate toward the continuous-compounding limit EXP(NominalRate)−1. At a nominal 0.12, that limit is approximately 0.127496851579.

The native example with Periods=12.9 gives the same result as Periods=12, because the source floors the count. NOMINAL is the inverse under the same whole-period convention: NOMINAL(EFFECTIVE(r;m);m) recovers r within numerical rounding. That identity was independently calculated beyond the eight listed native calls.

The source rejects NominalRate≤0 or Periods<1. Do not assume the mathematical zero-rate limit makes a zero input accepted by the function. Invalid-domain calls were not executed in this ordinary fixture. The source uses its approximate-floor helper; values extremely close to integers were not tested.

The tested ODF operation uses EFFECT, backed by the same core opcode whose English name is EFFECTIVE. It does not validate the separate EFFECT_ADD compatibility function or another application’s syntax. Percentage formatting multiplies the displayed value by 100; entering 12 rather than 0.12 would specify a very different nominal rate.

NOMINAL, power, exp.

• Function-specific release implementation

The generated ODF produced the informational load warning “Not all attributes could be read.” The sheet was hard-recalculated and saved separately. All eight ordinary function identities, inputs and results were reconciled; a stale SUM cache changed from 999999 to 3 and an uncached SUM returned 7. This establishes the stated examples, not every workbook style or invalid input. Other explanatory identities are independent calculations. The authoring-tool XLSX was not executed in OpenOffice, and its preview values are not the native results reported here.