Free · General investment calculators 🤑

Effective Rate and Compounding Balance

Compare nominal and effective annual interest with periodic or continuous compounding.

  • Formula & worked example
  • Private in your browser
  • No signup
Go to tool

Calculator inputs

Loading calculator…

How to use this calculator

  1. Enter the known values in the units shown. Results update as you type.
  2. Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
  3. Use the worked example to check the method. Reset restores the starting fields.

Use the result with context

Results are estimates for planning and education. Confirm rates, taxes, fees, and legal requirements with the relevant institution or a qualified professional before making a financial decision.

Formula and method

A nominal annual rate of 10%, compounded annually on 1000 for one year, gives an effective rate of 10% and a balance of 1100.

Effective rate = (1 + nominal/frequency)^frequency − 1; balance = principal × (1 + nominal/frequency)^(frequency × years).

Worked example

Enter these known values and leave the other values blank.

Annual interest rate
10 %
Compounding frequency
Annual
Term
1:0 yrs / mos
Initial balance
1000 USD
Periodic rate
10 %
Effective interest rate (EIR)
10 %
Final balance
1100 USD

Assumptions and limitations

  • No contributions, withdrawals, fees or tax are modeled. A year/month compound input uses years before the colon.
  • Weekly and average daily choices use captured calendar conventions of 52.1775 and 365.242 periods per year; 360-day and 365-day choices are separate.
  • Continuous mode uses exp(rate × years). Use positive starting principal, positive duration and a positive periodic growth factor.
  • Amounts use a single consistent currency. Currency selector conversion factors are a captured static snapshot; they are not current FX quotes.
  • Clear the unknown field before solving an inverse. Locks keep known values fixed; contradictory locked values require correction.
  • Domain review limits calculations to the documented finite scenario; original captured equations, inverses and unit options are retained.

Common questions

How should I interpret the example?

A nominal annual rate of 10%, compounded annually on 1000 for one year, gives an effective rate of 10% and a balance of 1100.

References

Require the documented finite model domain. Initial balance must be positive. Duration must be positive. The periodic growth factor must be positive.

Explore general investment calculators 🤑 or browse all finance calculators.