Compound Interest Tools

Monthly Compounding Calculator

Monthly Compound Interest Calculator

Calculate growth where interest is compounded monthly, one of the most common ways to model savings and investment growth.

Inputs

Your calculation

£
%

£
£
%

% annually
%
%

Outputs

Results

Enter your numbers and click calculate.

Final balance
£0.00
Total contributions
£0.00
Withdrawals: £0.00
Interest earned
£0.00
Tax/fees: £0.00

Year-by-year table

A yearly summary of balance, contributions and interest.

YearDepositsWithdrawalsInterestTax / feesEnd balance

What if I start 5 years earlier?

Calculate to see the comparison.

Simple vs compound interest

Calculate to see the comparison.

Excel formula

Copy a formula based on your current inputs.

=FV(...)

Growth chart

Visualise how your balance builds from the starting amount plus accrued interest.

Yearly chart

Month-by-month table

Click a year to expand the monthly breakdown.

Guide

How this calculator works

Monthly compounding splits the annual rate into 12 compounding periods. It is a useful default for many savings and investment examples because results are easy to compare against regular monthly deposits.

You can still change every input: currency, interest rate, years and months, compounding frequency, contribution timing, inflation and tax or fees. Use the share URL button to save a pre-filled version of the result.

FAQ

Monthly Compound Interest Calculator FAQ

Monthly compounding means interest is applied 12 times per year.

Yes. Set contribution mode to deposits, enter the deposit amount and choose monthly as the contribution frequency.

Enter the annual interest rate. The calculator converts it based on the compounding frequency.