Doubles in
10 yrs
Years until the amount doubles
See how $10,000 grows through compound interest — with a live calculator, growth curve, and rate comparison. Illustrative only, not investment advice.
$10,000 at 7% for 30 years (compounded monthly) becomes about $81,165.
Drag the rate and horizon and pick a compounding frequency to see what $10,000 becomes.
What $10,000 becomes — at 4, 6, 8, and 10% over 5 to 30 years (compounded monthly).
| Rate | 5 yrs | 10 yrs | 20 yrs | 30 yrs |
|---|---|---|---|---|
| 4% | $12,210 | $14,908 | $22,226 | $33,135 |
| 6% | $13,489 | $18,194 | $33,102 | $60,226 |
| 8% | $14,898 | $22,196 | $49,268 | $109,357 |
| 10% | $16,453 | $27,070 | $73,281 | $198,374 |
10 yrs
Years until the amount doubles
10 yrs
Year interest first exceeds the principal
$81.2k
$10,000 grows to about $81,165
7.23%
APY at 7% nominal, compounded monthly
$10,000 at 5% over 20 years — from annual to continuous, the final balance shifts only by a fraction.
| Compounding | Final balance (5%, 20 yrs) |
|---|---|
| Annually | $26,533 |
| Quarterly | $27,015 |
| Monthly | $27,126 |
| Daily | $27,181 |
| Continuously | $27,183 |
Compound interest means the interest you have already earned itself earns interest. That makes a balance grow not linearly but exponentially — unremarkable at first, then steep. The formula is A = P·(1 + r/n)^(n·t): A is the final balance, P the starting amount, r the annual rate as a decimal, n the compounding periods per year, and t the years.
Every figure on this page is illustrative only and not investment advice — real returns vary and are never guaranteed. For your own amounts, contributions, and rates, use the compound interest calculator. Background: Investopedia — Compound Interest.
At 7% a year, compounded monthly, $10,000 grows to about $81,165 over 30 years — with no further deposits, purely from compounding.
At 7%, $10,000 doubles after about 10 years. The Rule of 72 estimates this quickly: 72 ÷ 7 ≈ 10.3 years.
At 5% a year, compounded monthly, $10,000 grows to about $27,126 over 20 years.
A lot. Over 30 years, $10,000 grows to about $81,165 at 7%, but about $198,374 at 10%. A few extra percentage points nearly double the final figure — that is the leverage of time.
Only a small one. At 7% nominal, the effective annual rate (APY) with monthly compounding is about 7.23%. Moving from annual to monthly or daily changes the final figure by only fractions of a percent — the rate and the time horizon matter far more.
With the compound interest formula A = P·(1 + r/n)^(n·t): P is the starting amount ($10,000), r the annual rate, n the compounding periods per year, and t the years. All figures here are illustrative only and not investment advice.
Run your own numbers
The compound interest calculator opens pre-filled with $10,000 and lets you add contributions, rates, and terms.