Growth, inflation and asset mix
Compound Interest Calculator
See how daily, monthly, quarterly or annual compounding grows your savings, and how much of the final balance is your deposits versus interest earned.
Compound Interest Summary
EstimateGrowth Over Time
How This Calculator Works
Compound interest means you earn interest on your interest. This calculator shows how a deposit and monthly contributions grow over time, and how much the compounding schedule (daily, monthly, quarterly or yearly) changes the result.
The more often interest compounds, the higher the effective yield on the same stated rate: APY = (1 + r/m)^m − 1, where r is the stated annual rate and m is the number of compounding periods per year. The gap between daily and monthly is small. Time and what you contribute matter far more.
Frequently Asked Questions
What is the difference between APR and APY?
APR is the stated yearly rate, with no compounding counted. APY is what you actually earn in a year once compounding is included, so it is a little higher than the APR whenever interest compounds more than once a year.
What is the Rule of 72?
It is a quick way to estimate how long money takes to double: divide 72 by your annual return. At 8% a year, 72 ÷ 8 = 9, so your money doubles in roughly 9 years. It is a rough shortcut, so the real answer can differ a little.
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