📈 Compound Interest
$500 at 9% for 20 Years
Investing $500 at 9% annual compound interest for 20 years grows to $2,802. That's $2,302 earned in interest on top of your original $500.
Compound Interest Calculator
Australia 2026
$
%
$
Total value after 20 years
$2,802
Amount invested$500
Interest earned$2,302
Interest multiplier5.60×
Year-by-year growth
| Year | Balance | Interest |
|---|---|---|
| Yr 1 | $545 | +$45 |
| Yr 2 | $594 | +$49 |
| Yr 3 | $648 | +$53 |
| Yr 4 | $706 | +$58 |
| Yr 5 | $769 | +$64 |
| Yr 6 | $839 | +$69 |
| Yr 7 | $914 | +$75 |
| Yr 8 | $996 | +$82 |
| Yr 9 | $1,086 | +$90 |
| Yr 10 | $1,184 | +$98 |
| Yr 11 | $1,290 | +$107 |
| Yr 12 | $1,406 | +$116 |
| Yr 13 | $1,533 | +$127 |
| Yr 14 | $1,671 | +$138 |
| Yr 15 | $1,821 | +$150 |
| Yr 16 | $1,985 | +$164 |
| Yr 17 | $2,164 | +$179 |
| Yr 18 | $2,359 | +$195 |
| Yr 19 | $2,571 | +$212 |
| Yr 20 | $2,802 | +$231 |
Final balance after 20 years
$2,802
Invested
$500
Interest earned
$2,302
Multiplier
5.60×
How $500 grows at 9%
Compound interest earns returns on your returns — not just your original investment. At 9% per year, your money doubles every 8 years (the Rule of 72). Over 20 years, that compounds to a 5.60× multiplier.
In year 1, $500 earns $45 in interest. By year 20, the annual interest has grown to $231 — because each year's interest is calculated on a larger balance.
Year-by-year projection
| Year | Balance | Interest this year | Total interest | Growth |
|---|---|---|---|---|
| Year 1 | $545 | +$45 | $45 | 1.09× |
| Year 2 | $594 | +$49 | $94 | 1.19× |
| Year 3 | $648 | +$53 | $148 | 1.30× |
| Year 4 | $706 | +$58 | $206 | 1.41× |
| Year 5 | $769 | +$64 | $269 | 1.54× |
| Year 6 | $839 | +$69 | $339 | 1.68× |
| Year 7 | $914 | +$75 | $414 | 1.83× |
| Year 8 | $996 | +$82 | $496 | 1.99× |
| Year 9 | $1,086 | +$90 | $586 | 2.17× |
| Year 10 | $1,184 | +$98 | $684 | 2.37× |
| Year 11 | $1,290 | +$107 | $790 | 2.58× |
| Year 12 | $1,406 | +$116 | $906 | 2.81× |
| Year 13 | $1,533 | +$127 | $1,033 | 3.07× |
| Year 14 | $1,671 | +$138 | $1,171 | 3.34× |
| Year 15 | $1,821 | +$150 | $1,321 | 3.64× |
| Year 16 | $1,985 | +$164 | $1,485 | 3.97× |
| Year 17 | $2,164 | +$179 | $1,664 | 4.33× |
| Year 18 | $2,359 | +$195 | $1,859 | 4.72× |
| Year 19 | $2,571 | +$212 | $2,071 | 5.14× |
| Year 20 | $2,802 | +$231 | $2,302 | 5.60× |
Growth chart
Balance growth over 20 years
Principal
Interest earned
Frequently asked questions
Explore other scenarios
$500 for 20 years — other rates
$500 at 9% — other time horizons
Related calculators
Compound Interest Calculator
Australia 2026
$
%
$
Total value after 20 years
$2,802
Amount invested$500
Interest earned$2,302
Interest multiplier5.60×
Year-by-year growth
| Year | Balance | Interest |
|---|---|---|
| Yr 1 | $545 | +$45 |
| Yr 2 | $594 | +$49 |
| Yr 3 | $648 | +$53 |
| Yr 4 | $706 | +$58 |
| Yr 5 | $769 | +$64 |
| Yr 6 | $839 | +$69 |
| Yr 7 | $914 | +$75 |
| Yr 8 | $996 | +$82 |
| Yr 9 | $1,086 | +$90 |
| Yr 10 | $1,184 | +$98 |
| Yr 11 | $1,290 | +$107 |
| Yr 12 | $1,406 | +$116 |
| Yr 13 | $1,533 | +$127 |
| Yr 14 | $1,671 | +$138 |
| Yr 15 | $1,821 | +$150 |
| Yr 16 | $1,985 | +$164 |
| Yr 17 | $2,164 | +$179 |
| Yr 18 | $2,359 | +$195 |
| Yr 19 | $2,571 | +$212 |
| Yr 20 | $2,802 | +$231 |