Compound Interest Calculator
Explore growth from a starting balance with a fixed rate and a chosen compounding frequency.
Your result
FINANCIALEnter your values and select calculate.
On this page How it works & practical examples
How to use the Compound Interest Calculator
Choose a starting balance, a nominal annual rate and the number of years. Compounding adds each period’s interest to the balance that earns interest next period. Changing the frequency illustrates why a nominal rate and an effective annual yield are different. This tool focuses on a single starting amount; use the Savings Goal Calculator when planning regular deposits.
The calculation
Worked example
$10,000 at a 5% nominal annual rate, compounded monthly for 10 years, grows to about $16,470.09. The difference from the starting balance is $6,470.09.
Assumptions and limits
The rate remains constant and non-negative throughout the period. There are no recurring deposits, withdrawals, fees or taxes, and the output is not adjusted for inflation. A projected balance is a mathematical scenario, not a guaranteed investment outcome. Zero years returns the initial balance and a zero rate produces no interest.
Common questions
Can I enter an APY as the rate?
For an effective annual yield, choose annual compounding. Entering an APY and selecting monthly compounding would compound that yield again.
How do I include monthly contributions?
Use Savings Goal Calculator to find a regular deposit needed for a target balance. This tool intentionally isolates compound growth on one starting amount.