INTERACTIVE CALCULATOR

Compound interest calculator

Model monthly contributions and a constant assumed return. Contributions are added at the end of each month; returns are not guaranteed.

Your assumptions

Currency changes the display unit only; it does not convert exchange rates.

YOUR RESULT

Enter your assumptions to calculate.

How it is calculated

Monthly balance = previous balance × (1 + annual rate / 12) + contribution

Model monthly contributions and a constant assumed return. Contributions are added at the end of each month; returns are not guaranteed.

Use the result well

Model monthly contributions and a constant assumed return. Contributions are added at the end of each month; returns are not guaranteed.

Start by replacing the example inputs with your own figures. Keep currency, quantity units and time periods consistent. Change one input at a time to understand what causes a difference. You can reset the fields, copy the result or share a link containing the inputs you choose.

Assumptions and limits

The return is an assumption, compounded monthly. Contributions are made at month end. Taxes, fees, inflation and changes in return are excluded. Negative assumed returns are permitted; no future return is guaranteed.

Compare a second scenario

Keep a copy of your first result. Change one relevant value, such as the rate, duration, amount or consumption. Compare both the headline answer and the breakdown. A smaller monthly amount does not necessarily mean a smaller total cost.

Your information

Calculations are processed to return a result; we do not store the submitted financial values in a profile or send them to analytics. A shared scenario link includes the values you explicitly choose to share. These estimates are informational and do not replace an agreement, official bill or professional assessment.

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