Enter the starting principal, monthly contribution, annual rate, term, and compounding frequency; the final value updates as you type.
- Enter the starting principal and the monthly contribution.
- Enter the annual interest rate and the number of years.
- Pick a compounding frequency: monthly, annually, or daily.
- Read the final value, total contributed, and interest earned - they update automatically, no button to click.
Compound Interest Calculator
Project how a starting balance and regular contributions grow with compound interest over time.
Key features
- Enter the starting principal, monthly contribution, annual rate, term, and compounding frequency; the final value, total contributed, and interest earned update as you type - there is no submit button.
- The principal, rate, and compounding settings stay in the browser - the projection is computed on this device, with no upload and no account.
When to use it
Use it to see what a balance becomes after a set number of years, or to compare how monthly against annual compounding changes the final figure. The frequency selector also offers a daily option alongside monthly and annual, and each choice re-prices your monthly contribution into a matching per-period amount before the projection is calculated. Switching between the three lets you see how the schedule on which interest is applied - twelve times a year, once a year, or every day - nudges the same principal and rate to a different final figure.
What the output is
Output is a single USD figure with no growth chart or export - for a jurisdiction-specific plan that accounts for taxes and inflation, use this as a quick sanity check, then talk to a licensed advisor.
Results are an estimate based on a constant rate; actual returns vary and this is not financial advice.
Frequently Asked Questions
What does Compound Interest Calculator do?
Project how a starting balance and regular contributions grow with compound interest over time.
When should I reach for compound interest calculator?
Reach for it when you want to see how a starting principal plus a monthly contribution grows once compounding is applied each period. Enter your principal, monthly contribution, annual interest rate, and term in years, and it returns the final value, total contributed, and interest earned, recalculated live as you change any field.
Does this account for taxes or inflation?
No. Results are an estimate based on a constant rate; they do not account for taxes, inflation, or fees, and this is not financial advice.
Is anything I type uploaded or saved?
No. The math runs locally in the browser - no upload, no account, and nothing is stored beyond the current page session.