📈 Compound Interest

$200,000 at 9% for 20 Years

Investing $200,000 at 9% annual compound interest for 20 years grows to $1,120,882. That's $920,882 earned in interest on top of your original $200,000.

If you want to adjust the return assumption, extend the timeframe, or add regular contributions, use the compound interest calculator.

If you want the plain-English explanation behind the numbers, read our guide to compound interest.

Compound Interest Calculator
Australia 2026
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Total value after 20 years
$1,120,882
Amount invested$200,000
Interest earned$920,882
Interest multiplier5.60×
Year-by-year growth
YearBalanceInterest
Yr 1$218,000+$18,000
Yr 2$237,620+$19,620
Yr 3$259,006+$21,386
Yr 4$282,316+$23,311
Yr 5$307,725+$25,408
Yr 6$335,420+$27,695
Yr 7$365,608+$30,188
Yr 8$398,513+$32,905
Yr 9$434,379+$35,866
Yr 10$473,473+$39,094
Yr 11$516,085+$42,613
Yr 12$562,533+$46,448
Yr 13$613,161+$50,628
Yr 14$668,345+$55,184
Yr 15$728,496+$60,151
Yr 16$794,061+$65,565
Yr 17$865,527+$71,466
Yr 18$943,424+$77,897
Yr 19$1,028,332+$84,908
Yr 20$1,120,882+$92,550
Final balance after 20 years
$1,120,882
Invested
$200,000
Interest earned
$920,882
Multiplier
5.60×

How $200,000 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, $200,000 earns $18,000 in interest. By year 20, the annual interest has grown to $92,550 — because each year's interest is calculated on a larger balance.

This is why longer holding periods matter so much. The later years do more of the heavy lifting, especially once the balance is large enough to generate bigger dollar returns each year.

$200,000 for 20 years at different rates
RateFinal balanceInterest earnedMultiplier
4%$438,225$238,2252.19×
5%$530,660$330,6602.65×
6%$641,427$441,4273.21×
7%$773,937$573,9373.87×
8%$932,191$732,1914.66×
9% ◀$1,120,882$920,8825.60×
10%$1,345,500$1,145,5006.73×

Year-by-year projection

YearBalanceInterest this yearTotal interestGrowth
Year 1$218,000+$18,000$18,0001.09×
Year 2$237,620+$19,620$37,6201.19×
Year 3$259,006+$21,386$59,0061.30×
Year 4$282,316+$23,311$82,3161.41×
Year 5$307,725+$25,408$107,7251.54×
Year 6$335,420+$27,695$135,4201.68×
Year 7$365,608+$30,188$165,6081.83×
Year 8$398,513+$32,905$198,5131.99×
Year 9$434,379+$35,866$234,3792.17×
Year 10$473,473+$39,094$273,4732.37×
Year 11$516,085+$42,613$316,0852.58×
Year 12$562,533+$46,448$362,5332.81×
Year 13$613,161+$50,628$413,1613.07×
Year 14$668,345+$55,184$468,3453.34×
Year 15$728,496+$60,151$528,4963.64×
Year 16$794,061+$65,565$594,0613.97×
Year 17$865,527+$71,466$665,5274.33×
Year 18$943,424+$77,897$743,4244.72×
Year 19$1,028,332+$84,908$828,3325.14×
Year 20$1,120,882+$92,550$920,8825.60×

Growth chart

Balance growth over 20 years
$280k$560k$841k$1.1MYr1Yr5Yr10Yr15Yr20
Principal
Interest earned

Frequently asked questions

Related compound interest scenarios

Use these nearby examples to compare what changes when you keep the same starting balance, extend the investing period, or test a more aggressive return assumption.

Compound interest guide and tools

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