📈 Compound Interest

$100,000 at 10% for 20 Years

Investing $100,000 at 10% annual compound interest for 20 years grows to $672,750. That's $572,750 earned in interest on top of your original $100,000.

Compound Interest Calculator
Australia 2026
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Total value after 20 years
$672,750
Amount invested$100,000
Interest earned$572,750
Interest multiplier6.73×
Year-by-year growth
YearBalanceInterest
Yr 1$110,000+$10,000
Yr 2$121,000+$11,000
Yr 3$133,100+$12,100
Yr 4$146,410+$13,310
Yr 5$161,051+$14,641
Yr 6$177,156+$16,105
Yr 7$194,872+$17,716
Yr 8$214,359+$19,487
Yr 9$235,795+$21,436
Yr 10$259,374+$23,579
Yr 11$285,312+$25,937
Yr 12$313,843+$28,531
Yr 13$345,227+$31,384
Yr 14$379,750+$34,523
Yr 15$417,725+$37,975
Yr 16$459,497+$41,772
Yr 17$505,447+$45,950
Yr 18$555,992+$50,545
Yr 19$611,591+$55,599
Yr 20$672,750+$61,159
Final balance after 20 years
$672,750
Invested
$100,000
Interest earned
$572,750
Multiplier
6.73×

How $100,000 grows at 10%

Compound interest earns returns on your returns — not just your original investment. At 10% per year, your money doubles every 7.2 years (the Rule of 72). Over 20 years, that compounds to a 6.73× multiplier.

In year 1, $100,000 earns $10,000 in interest. By year 20, the annual interest has grown to $61,159 — because each year's interest is calculated on a larger balance.

$100,000 for 20 years at different rates
RateFinal balanceInterest earnedMultiplier
4%$219,112$119,1122.19×
5%$265,330$165,3302.65×
6%$320,714$220,7143.21×
7%$386,968$286,9683.87×
8%$466,096$366,0964.66×
9%$560,441$460,4415.60×
10% ◀$672,750$572,7506.73×

Year-by-year projection

YearBalanceInterest this yearTotal interestGrowth
Year 1$110,000+$10,000$10,0001.10×
Year 2$121,000+$11,000$21,0001.21×
Year 3$133,100+$12,100$33,1001.33×
Year 4$146,410+$13,310$46,4101.46×
Year 5$161,051+$14,641$61,0511.61×
Year 6$177,156+$16,105$77,1561.77×
Year 7$194,872+$17,716$94,8721.95×
Year 8$214,359+$19,487$114,3592.14×
Year 9$235,795+$21,436$135,7952.36×
Year 10$259,374+$23,579$159,3742.59×
Year 11$285,312+$25,937$185,3122.85×
Year 12$313,843+$28,531$213,8433.14×
Year 13$345,227+$31,384$245,2273.45×
Year 14$379,750+$34,523$279,7503.80×
Year 15$417,725+$37,975$317,7254.18×
Year 16$459,497+$41,772$359,4974.59×
Year 17$505,447+$45,950$405,4475.05×
Year 18$555,992+$50,545$455,9925.56×
Year 19$611,591+$55,599$511,5916.12×
Year 20$672,750+$61,159$572,7506.73×

Growth chart

Balance growth over 20 years
$168k$336k$505k$673kYr1Yr5Yr10Yr15Yr20
Principal
Interest earned

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