Calculate compound interest with monthly or annual compounding — see year-by-year growth
Compound interest is the mathematical foundation of both long-term investing and the true cost of carrying debt. Unlike simple interest, which is calculated only on the original principal, compound interest calculates on the principal plus all previously earned interest, producing exponential growth over time. A single investment at a steady annual rate compounds dramatically over longer periods compared to simple interest — a difference that grows more pronounced with every passing year. This compound interest calculator shows the final balance, total interest earned, and a year-by-year breakdown for any principal, interest rate, compounding frequency (daily, monthly, quarterly, or annually), and investment duration. People reach for this tool in a wide variety of real financial situations. A 28-year-old contributing to a Roth IRA might use it to see how an initial $6,000 deposit grows to more than $45,000 over 30 years at a 7% annual return, helping them stay motivated to invest early. Someone carrying a $5,000 balance on a credit card charging 22% APR compounded daily can use the calculator to see exactly how much that debt balloons if left unpaid for three years — a sobering figure that often accelerates repayment decisions. Parents planning for college costs frequently use it to compare a 529 savings plan's projected growth against tuition inflation, adjusting contribution amounts until the numbers align. Personal finance enthusiasts, students learning economics, financial advisors running quick client scenarios, and anyone comparing savings account or CD offers all benefit from having a fast, accurate compounding tool at hand. All calculations run entirely in your browser. No data is sent to any server, so you can enter real account balances and rates without any privacy concerns. Adjust the inputs and the results update instantly, making it easy to model multiple scenarios side by side and understand exactly how time, rate, and compounding frequency each affect your final outcome.
Formula
A = P(1 + r/n)^(nt)
Final Amount
$20,096.61
Total Interest Earned
$10,096.61
Principal
$10,000.00
Effective Annual Rate (EAR)
7.2290%
| Year | Balance | Interest Earned |
|---|---|---|
| Year 1 | $10,722.90 | +$722.90 |
| Year 2 | $11,498.06 | +$775.16 |
| Year 3 | $12,329.26 | +$831.20 |
| Year 4 | $13,220.54 | +$891.28 |
| Year 5 | $14,176.25 | +$955.71 |
| Year 6 | $15,201.06 | +$1,024.80 |
| Year 7 | $16,299.94 | +$1,098.89 |
| Year 8 | $17,478.26 | +$1,178.32 |
| Year 9 | $18,741.77 | +$1,263.51 |
| Year 10 | $20,096.61 | +$1,354.84 |