Compound Interest Calculator
Project the growth of a single deposit at any rate, with daily, monthly, quarterly or yearly compounding.
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How the math works
Standard compound interest formula: A = P × (1 + r/n)n·t, where P is principal, r the annual rate as a decimal, n the number of compounding periods per year, and t the years. Results assume a fixed rate, no withdrawals, no taxes and no fees.
FAQ
What's the difference between simple and compound interest?
Simple interest is calculated only on the original principal. Compound interest is calculated on the principal plus any previously earned interest, which is why balances grow faster over time.
What's the difference between APR and APY?
APR is the simple annual rate before compounding. APY is the effective rate after compounding is applied. APY is always greater than or equal to APR.
Can I add monthly contributions?
This page focuses on a single lump-sum deposit. To project regular monthly contributions on top of a starting balance, use the Savings Growth Calculator.