Compound Interest Calculator
Enter an initial amount, interest rate, term, and optional monthly contribution to project future value with compound interest.
An estimate assuming a constant rate of return, which real investments don't provide. Not investment advice.
Frequently asked questions
Why does compounding frequency (monthly vs. annually) change the result?+
More frequent compounding means interest starts earning its own interest sooner. Monthly compounding at the same annual rate produces a slightly higher final value than annual compounding, because each month's interest gets added to the balance immediately instead of waiting a full year.
Is this a realistic projection for the stock market?+
No, it assumes a constant rate of return every period, which real investments never actually deliver; markets go up and down. Treat this as a simplified planning estimate, not a prediction, and definitely not investment advice.
How are monthly contributions handled?+
Each contribution is assumed to happen at a regular interval matching your chosen compounding frequency, and it starts earning returns from the period it's added, the same way a real recurring investment would.