Compound Interest Calculator
About Compound Interest Calculator
The compound interest calculator estimates future balance, contributions, and earned interest using monthly compounding over time.
How to Use
The compound interest calculator estimates future balance, contributions, and earned interest using monthly compounding over time. Enter the Loan amount, Monthly contribution, Annual rate, and Years values and review the Final balance, Total contributions, and Interest earned outputs after you calculate.
- Open the calculator : Use Compound Interest Calculator from the Finance category.
- Check the inputs : Review the required values and any optional settings.
- Read the formula : Use the formula and notes below to understand how the result is produced.
Common Questions
What does the Compound Interest Calculator estimate?
Project savings or investment growth with monthly contributions.
What can change the estimate?
This is an estimate, so taxes, fees, payment timing, compounding, and changing returns can move the result.
What is the Rule of 72 in compound interest?
The Rule of 72 is a mental math shortcut to estimate how long it takes to double an investment. Divide 72 by your annual compound interest rate. For example, at an 8% interest rate, your money will double in approximately 9 years (72 ÷ 8 = 9).
How does compounding frequency affect total returns?
The more frequently interest is compounded, the faster your money grows. Daily compounding yields slightly more than monthly compounding, and monthly yields more than annual, because the interest you earn begins generating its own interest sooner.
Inputs
- Loan amount
- Monthly contribution
- Annual rate
- Years
Outputs
- Final balance
- Total contributions
- Interest earned
Formula
Each month: balance = balance x (1 + monthly rate) + monthly contribution.