Accounting Share · Interest, loans & valuation
Effective Annual Interest Rate Calculator
Translate a nominal annual rate into an effective annual rate that reflects compounding within the year.
The interactive calculator requires JavaScript. The formula and worked example below remain available.
01 / Enter your figures
Make the numbers yours.
Use one currency and consistent time periods. Amounts are shown in your input currency units; no currency conversion is performed.
02 / See the working
Your calculation
Enter your figures, then choose Calculate. Or load the worked example.
03 / Understand the method
Formula and method
EAR = (1 + Nominal annual rate ÷ Frequency)^Frequency − 1
Translate a nominal annual rate into an effective annual rate that reflects compounding within the year.
How to use this calculator
- Collect the figures for the same entity, currency and reporting period.
- Enter each input using its label and unit. For percentages, enter 15 to mean 15%.
- Choose Calculate, inspect the breakdown and compare the result with your assumptions.
- Change one input to explore a scenario. Recalculate after edits; display rounding does not round the underlying calculation.
Inputs at a glance
- Nominal annual rate (%): A percentage number rather than a decimal fraction.
- Compounding periods per year: A nonnegative numeric input in the units specified by the label.
Worked example
Follow one calculation.
- Nominal annual rate (%)
- 12
- Compounding periods per year
- 12
- Calculated result
- 12.6825%
Load this example in the interactive form to inspect the intermediate amounts.
Assumptions and interpretation
This is a mathematical effective rate without fees. It is not necessarily the legally defined APR or APY for a financial product.
The output is a model based on the figures entered. Check source records and use the accounting or contractual definitions relevant to your task before relying on a result.
Questions about this tool
What does the effective annual interest rate calculation measure?
Translate a nominal annual rate into an effective annual rate that reflects compounding within the year.
Which assumptions can change the result?
This is a mathematical effective rate without fees. It is not necessarily the legally defined APR or APY for a financial product.
Why can displayed totals differ slightly from my spreadsheet?
Calculations use the unrounded input values. Only the display is rounded. Use four or six decimal places to inspect small differences, and check the timing, sign conventions and rounding policy in your spreadsheet.
Reference and further learning
Time value of money and loans. These original learning examples apply the displayed formula; the reference does not certify or endorse this calculator.
Look up an accounting term · Practise with accounting questions
Formula and worked example checked 4 November 2026. Calculations run in your browser without sending the entered figures to Accounting Share. Report a calculation issue with the tool name, example inputs and expected result; avoid sharing confidential records.
