EFFECT Function (LibreOffice Calc)
The EFFECT function returns the effective annual interest rate given a nominal annual rate and compounding frequency. It is used in loan modeling, savings analysis, and interest-rate conversions.
Compatibility
▾| Excel | ✔ |
| Gnumeric | ✔ |
| Google_sheets | ✔ |
| Libreoffice | ✔ |
| Numbers | ✔ |
| Onlyoffice | ✔ |
| Openoffice | ✔ |
| Wps | ✔ |
| Zoho | ✔ |
What the EFFECT Function Does ▾
- Converts nominal rate → effective annual rate
- Accounts for compounding frequency
- Useful for comparing financial products
- Works with any compounding period count
Syntax ▾
EFFECT(nominal_rate; npery)
Arguments
-
nominal_rate:
The stated annual interest rate (not adjusted for compounding). -
npery:
Number of compounding periods per year (e.g., 12 for monthly).
Basic Examples ▾
Monthly compounding
=EFFECT(0.12; 12)
→ 0.126825 (12.6825%)
Quarterly compounding
=EFFECT(0.10; 4)
→ 0.103812 (10.3812%)
Daily compounding (365)
=EFFECT(0.05; 365)
Annual compounding (same as nominal)
=EFFECT(0.08; 1)
→ 0.08
Advanced Examples ▾
Compare two loan products
=EFFECT(A1; B1) < EFFECT(A2; B2)
Convert effective → nominal (inverse via NOMINAL)
=NOMINAL(EFFECT(A1; A2); A2)
Compute EAR for semiannual compounding
=EFFECT(rate; 2)
Build a compounding comparison table
=EFFECT($B$1; A2)
Use EFFECT inside a loan model
=FV(EFFECT(rate; 12); years; -payment; 0)
Convert nominal → effective → monthly rate
=((1 + EFFECT(A1; A2))^(1/12)) - 1
Edge Cases and Behavior Details ▾
EFFECT returns a decimal rate, not a percentage
Format as percentage if needed.
Behavior details
- nominal_rate must be ≥ 0
- npery must be ≥ 1
- npery must be an integer
- Uses formula:
[ (1 + \frac{r}{n})^n - 1 ]
Invalid input → Err:502
Common Errors and Fixes ▾
Err:502 — Invalid argument
Cause:
- npery < 1
- non-integer compounding periods
- negative nominal rate
Fix:
- Ensure npery is a positive integer
- Use ABS() if needed
Wrong effective rate
Cause:
- Confusing nominal vs effective
- Incorrect compounding frequency
Fix:
- Confirm compounding periods (12, 4, 2, 365)
Best Practices ▾
- Always use EFFECT when comparing financial products
- Use NOMINAL for the reverse conversion
- Document compounding assumptions clearly
- Use EFFECT for APR/EAR comparisons
- Use consistent formatting (percentage)
EFFECT is essential for apples‑to‑apples comparisons of interest rates — it reveals the true annual cost or return after compounding.
Related Patterns and Alternatives ▾
- NOMINAL — convert effective → nominal
- RATE / FV / PV — time‑value functions
- IPMT / PPMT — interest and principal breakdown
- Compound interest formulas — manual modeling
By mastering EFFECT, you can build accurate, transparent interest‑rate models in LibreOffice Calc.