Investors
Compound Interest Calculator
See how compounding grows your money over time, add monthly contributions, set your rate, and model best- and worst-case scenarios with a variance range.
Your Numbers
Future Value · 20 Years
$300,851
at 7% compounded monthly
If 9.0%
$394,035
If 5.0%
$232,643
Breakdown
Total Invested
$130,000
Interest Earned
$170,851
Ending Balance
$300,851
Year-by-Year Growth
| Year | Contributions | Interest | Balance |
|---|---|---|---|
| 1 | $6,000 | $919 | $16,919 |
| 2 | $6,000 | $1,419 | $24,339 |
| 3 | $6,000 | $1,956 | $32,294 |
| 4 | $6,000 | $2,531 | $40,825 |
| 5 | $6,000 | $3,148 | $49,973 |
| 6 | $6,000 | $3,809 | $59,782 |
| 7 | $6,000 | $4,518 | $70,299 |
| 8 | $6,000 | $5,278 | $81,578 |
| 9 | $6,000 | $6,094 | $93,671 |
| 10 | $6,000 | $6,968 | $106,639 |
| 11 | $6,000 | $7,905 | $120,544 |
| 12 | $6,000 | $8,910 | $135,455 |
| 13 | $6,000 | $9,988 | $151,443 |
| 14 | $6,000 | $11,144 | $168,587 |
| 15 | $6,000 | $12,383 | $186,971 |
| 16 | $6,000 | $13,712 | $206,683 |
| 17 | $6,000 | $15,137 | $227,820 |
| 18 | $6,000 | $16,665 | $250,486 |
| 19 | $6,000 | $18,304 | $274,790 |
| 20 | $6,000 | $20,061 | $300,851 |
Thinking about real estate as part of your portfolio?
Investment property can compound your wealth through appreciation, rental income, and tax advantages.
Explore Investment PropertiesThis calculator is for educational purposes only and assumes a constant rate of return; actual investment returns vary and are not guaranteed. It is not investment advice. Consult a licensed financial advisor.
How the compound interest calculator works
This tool projects how an investment grows from a starting balance, regular contributions, an annual rate, and a compounding frequency. It uses the future value formula FV = P(1 + r/n)^(nt) for the principal, then adds the future value of your recurring contributions, so both the lump sum and every deposit earn compounding returns over time.
Start with $25,000, add $500 a month at an 8% annual rate compounded monthly for 20 years. The principal grows to about $123,170, and the contributions add roughly $294,510, for a total near $417,680. You contributed $145,000 of that, so compounding generated about $272,680 in growth.
For South Florida investors weighing real estate against the market, this shows the opportunity cost of a down payment left uninvested and how steady contributions compound. Whether you are saving for a first home, a rental down payment, or retirement beyond property, seeing the long-run curve helps you size contributions and set a realistic timeline.