Saving & Growing
Compound Interest Calculator
Your numbers
An assumption, not a promise. Investments can lose value, and returns vary from year to year.
Compounding
Balance after 20 years
$196,665
$114,665 of that is growth on top of the $82,000 you put in.
- Total contributions
- $82,000
- Total growth
- $114,665
- Final balance
- $196,665
Year-by-year balance
| Year | Contributions | Growth | Balance |
|---|---|---|---|
| 1 | $13,600 | $841 | $14,441 |
| 2 | $17,200 | $2,002 | $19,202 |
| 3 | $20,800 | $3,508 | $24,308 |
| 4 | $24,400 | $5,383 | $29,783 |
| 5 | $28,000 | $7,654 | $35,654 |
| 6 | $31,600 | $10,349 | $41,949 |
| 7 | $35,200 | $13,500 | $48,700 |
| 8 | $38,800 | $17,138 | $55,938 |
| 9 | $42,400 | $21,299 | $63,699 |
| 10 | $46,000 | $26,022 | $72,022 |
| 11 | $49,600 | $31,346 | $80,946 |
| 12 | $53,200 | $37,316 | $90,516 |
| 13 | $56,800 | $43,977 | $100,777 |
| 14 | $60,400 | $51,380 | $111,780 |
| 15 | $64,000 | $59,578 | $123,578 |
| 16 | $67,600 | $68,629 | $136,229 |
| 17 | $71,200 | $78,595 | $149,795 |
| 18 | $74,800 | $89,542 | $164,342 |
| 19 | $78,400 | $101,540 | $179,940 |
| 20 | $82,000 | $114,665 | $196,665 |
Results are estimates for planning only and assume the numbers you enter stay the same. They are not an offer of credit or financial advice. Confirm actual terms with the lender, bank or provider.
How it works
Behind the numbers
Compound interest means you earn returns on your past returns, not just on what you contributed. The calculator adds your monthly contribution at the end of each month and applies growth at the rate and compounding frequency you choose.
The rate is an assumption you set. Savings accounts and CDs pay a stated rate, while investments like stock funds have no guaranteed return and can fall in value. Use a conservative rate for planning, and treat the result as an illustration rather than a forecast.
Tips
- Time is the biggest lever: starting earlier usually matters more than contributing more later.
- Small, regular contributions add up because each one has years to compound.
- Fees and taxes reduce real-world returns, so a lower rate is a safer planning number.
Quick answers
Common questions
What is compound interest?
It's interest or investment growth calculated on both your original money and the growth it has already earned. Over long periods, that growth on growth can become a large part of your balance.
What rate should I use?
For savings, use your account's APY. For long-term investing, many people plan with a conservative rate below historical market averages, since returns aren't guaranteed and vary year to year.
Does compounding frequency matter much?
It matters a little. More frequent compounding produces slightly more growth at the same rate, but the rate, your contributions and time matter far more.