Compound Interest Calculator
The Compound Interest Calculator shows how a single lump-sum investment grows over time based on your interest rate, compounding frequency, and time horizon.
Advertisement
Advertisement
How This Tool Works
Enter your starting principal, annual interest rate, compounding frequency, and time horizon to see the future value and interest earned.
Formula & Method
Future value = P × (1 + r/n)^(n×t), where P is principal, r is the annual interest rate, n is compounding periods per year, and t is years.
Example Calculation
A $10,000 principal at 5% annual interest, compounded monthly for 15 years, grows to about $21,137 — earning $11,137 in interest.
Frequently Asked Questions
Does compounding frequency matter much?+
It has a modest effect — more frequent compounding (daily vs. annually) yields slightly more growth for the same stated rate, though the difference shrinks at lower rates.
What's the difference between this and the Savings Calculator?+
This tool models a single lump-sum investment with no further contributions. Use the Savings Calculator if you're also adding money regularly.
Is this the same as APY?+
Annual Percentage Yield (APY) already factors in compounding frequency, while this calculator lets you see the effect of different compounding schedules on a stated annual rate.
Advertisement
Related Tools
Savings Calculator
Project how your savings will grow with regular contributions.
Use tool →FinanceBudget Calculator
Compare your spending to the popular 50/30/20 budgeting rule.
Use tool →FinanceMortgage Calculator
Estimate your monthly mortgage payment including taxes and insurance.
Use tool →FinanceLoan Payment Calculator
Calculate the monthly payment for any fixed-rate loan.
Use tool →