Future Value
See the final balance after your chosen number of years.
CALCULATOR / SAVINGS
Free Compound Interest Calculator
See how your savings or investments could grow over time. Set a starting amount, monthly contribution, interest rate and compounding frequency, and view a year-by-year breakdown.
An illustration only: returns are never guaranteed and taxes and fees are not included. Your numbers stay in your browser.
✓ Free to use · No signup required · Processed in your browser
Compound Interest Calculator workspace
ENTER AMOUNT, RATE AND YEARS · CALCULATE · SEE YEAR-BY-YEAR GROWTH
Enter your starting amount, rate and number of years.
Future value
Total contributed—
Interest earned—
Starting amount—
Growth—
| Year | Contributed | Interest | Balance |
|---|
Illustration only. Contributions are added at the end of each month and the rate is assumed constant. Real investments vary and returns are not guaranteed; taxes and fees are not included.
COMPOUND INTEREST WORKSPACEMOSANKIT / CALCULATORS
THE BASICS
What Is Compound Interest?
Compound interest is interest earned on both your original money and on the interest it has already earned. Over many years this "interest on interest" makes growth accelerate, which is why starting early and contributing regularly matters so much.
How often interest is compounded — yearly, monthly or daily — also changes the result slightly. This calculator lets you compare them and add a regular monthly contribution.
BUILT FOR THE JOB
Key Features of MoSanKit Compound Interest Calculator
Monthly Contributions
Add regular deposits and see how much they add.
Compounding Frequency
Annually, semi-annually, quarterly, monthly or daily.
Year-by-Year Table
Contributions, interest and balance at the end of every year.
Clear Breakdown
Separate totals for money you put in and interest earned.
Private by Design
Everything runs in your browser.
QUICK AND SIMPLE
How to Calculate Compound Interest
01 / START
Enter your starting amount
What you have to begin with.
02 / ADD
Add a monthly contribution
Optional regular deposits.
03 / RATE
Set rate, years and compounding
The expected annual rate and how long.
04 / REVIEW
Review the growth
See your totals and the yearly table.
MADE FOR EVERYDAY WORK
Who Can Use This Tool?
SaversSee what regular saving could become.
InvestorsIllustrate long-term growth.
StudentsUnderstand how compounding works.
ParentsPlan savings for children.
Retirement PlannersEstimate long-term balances.
Financial EducatorsDemonstrate the power of time.
GOOD TO KNOW
A few things, answered.
Quick answers about using the MoSanKit Compound Interest Calculator.
A = P(1 + r/n)^(nt), where P is the principal, r the annual rate, n the number of times interest compounds per year and t the number of years. With monthly contributions, each deposit also earns interest from the month it is added.
At the end of each month, after that month's interest is applied.
More frequent compounding gives slightly more growth. For example, 7% compounded monthly grows a little faster than 7% compounded annually.
No. Real investments rise and fall, and interest rates change. This is an illustration based on a constant rate.
No. Those would reduce your real return. Consider them when planning.
No. The calculation is done in your browser and nothing is sent or saved.
KEEP BUILDING
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time to grow.
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