📈 Compound Interest
$100,000 at 8% for 20 Years
Investing $100,000 at 8% annual compound interest for 20 years grows to $466,096. That's $366,096 earned in interest on top of your original $100,000.
Compound Interest Calculator
Australia 2026
$
%
$
Total value after 20 years
$466,096
Amount invested$100,000
Interest earned$366,096
Interest multiplier4.66×
Year-by-year growth
| Year | Balance | Interest |
|---|---|---|
| Yr 1 | $108,000 | +$8,000 |
| Yr 2 | $116,640 | +$8,640 |
| Yr 3 | $125,971 | +$9,331 |
| Yr 4 | $136,049 | +$10,078 |
| Yr 5 | $146,933 | +$10,884 |
| Yr 6 | $158,687 | +$11,755 |
| Yr 7 | $171,382 | +$12,695 |
| Yr 8 | $185,093 | +$13,711 |
| Yr 9 | $199,900 | +$14,807 |
| Yr 10 | $215,892 | +$15,992 |
| Yr 11 | $233,164 | +$17,271 |
| Yr 12 | $251,817 | +$18,653 |
| Yr 13 | $271,962 | +$20,145 |
| Yr 14 | $293,719 | +$21,757 |
| Yr 15 | $317,217 | +$23,498 |
| Yr 16 | $342,594 | +$25,377 |
| Yr 17 | $370,002 | +$27,408 |
| Yr 18 | $399,602 | +$29,600 |
| Yr 19 | $431,570 | +$31,968 |
| Yr 20 | $466,096 | +$34,526 |
Final balance after 20 years
$466,096
Invested
$100,000
Interest earned
$366,096
Multiplier
4.66×
How $100,000 grows at 8%
Compound interest earns returns on your returns — not just your original investment. At 8% per year, your money doubles every 9 years (the Rule of 72). Over 20 years, that compounds to a 4.66× multiplier.
In year 1, $100,000 earns $8,000 in interest. By year 20, the annual interest has grown to $34,526 — 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 | $108,000 | +$8,000 | $8,000 | 1.08× |
| Year 2 | $116,640 | +$8,640 | $16,640 | 1.17× |
| Year 3 | $125,971 | +$9,331 | $25,971 | 1.26× |
| Year 4 | $136,049 | +$10,078 | $36,049 | 1.36× |
| Year 5 | $146,933 | +$10,884 | $46,933 | 1.47× |
| Year 6 | $158,687 | +$11,755 | $58,687 | 1.59× |
| Year 7 | $171,382 | +$12,695 | $71,382 | 1.71× |
| Year 8 | $185,093 | +$13,711 | $85,093 | 1.85× |
| Year 9 | $199,900 | +$14,807 | $99,900 | 2.00× |
| Year 10 | $215,892 | +$15,992 | $115,892 | 2.16× |
| Year 11 | $233,164 | +$17,271 | $133,164 | 2.33× |
| Year 12 | $251,817 | +$18,653 | $151,817 | 2.52× |
| Year 13 | $271,962 | +$20,145 | $171,962 | 2.72× |
| Year 14 | $293,719 | +$21,757 | $193,719 | 2.94× |
| Year 15 | $317,217 | +$23,498 | $217,217 | 3.17× |
| Year 16 | $342,594 | +$25,377 | $242,594 | 3.43× |
| Year 17 | $370,002 | +$27,408 | $270,002 | 3.70× |
| Year 18 | $399,602 | +$29,600 | $299,602 | 4.00× |
| Year 19 | $431,570 | +$31,968 | $331,570 | 4.32× |
| Year 20 | $466,096 | +$34,526 | $366,096 | 4.66× |
Growth chart
Balance growth over 20 years
Principal
Interest earned
Frequently asked questions
Explore other scenarios
$100,000 for 20 years — other rates
$100,000 at 8% — other time horizons
Related calculators
Compound Interest Calculator
Australia 2026
$
%
$
Total value after 20 years
$466,096
Amount invested$100,000
Interest earned$366,096
Interest multiplier4.66×
Year-by-year growth
| Year | Balance | Interest |
|---|---|---|
| Yr 1 | $108,000 | +$8,000 |
| Yr 2 | $116,640 | +$8,640 |
| Yr 3 | $125,971 | +$9,331 |
| Yr 4 | $136,049 | +$10,078 |
| Yr 5 | $146,933 | +$10,884 |
| Yr 6 | $158,687 | +$11,755 |
| Yr 7 | $171,382 | +$12,695 |
| Yr 8 | $185,093 | +$13,711 |
| Yr 9 | $199,900 | +$14,807 |
| Yr 10 | $215,892 | +$15,992 |
| Yr 11 | $233,164 | +$17,271 |
| Yr 12 | $251,817 | +$18,653 |
| Yr 13 | $271,962 | +$20,145 |
| Yr 14 | $293,719 | +$21,757 |
| Yr 15 | $317,217 | +$23,498 |
| Yr 16 | $342,594 | +$25,377 |
| Yr 17 | $370,002 | +$27,408 |
| Yr 18 | $399,602 | +$29,600 |
| Yr 19 | $431,570 | +$31,968 |
| Yr 20 | $466,096 | +$34,526 |