📈 Compound Interest

$20,000 at 10% for 20 Years

Investing $20,000 at 10% annual compound interest for 20 years grows to $134,550. That's $114,550 earned in interest on top of your original $20,000.

Compound Interest Calculator
Australia 2026
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%
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Total value after 20 years
$134,550
Amount invested$20,000
Interest earned$114,550
Interest multiplier6.73×
Year-by-year growth
YearBalanceInterest
Yr 1$22,000+$2,000
Yr 2$24,200+$2,200
Yr 3$26,620+$2,420
Yr 4$29,282+$2,662
Yr 5$32,210+$2,928
Yr 6$35,431+$3,221
Yr 7$38,974+$3,543
Yr 8$42,872+$3,897
Yr 9$47,159+$4,287
Yr 10$51,875+$4,716
Yr 11$57,062+$5,187
Yr 12$62,769+$5,706
Yr 13$69,045+$6,277
Yr 14$75,950+$6,905
Yr 15$83,545+$7,595
Yr 16$91,899+$8,354
Yr 17$101,089+$9,190
Yr 18$111,198+$10,109
Yr 19$122,318+$11,120
Yr 20$134,550+$12,232
Final balance after 20 years
$134,550
Invested
$20,000
Interest earned
$114,550
Multiplier
6.73×

How $20,000 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, $20,000 earns $2,000 in interest. By year 20, the annual interest has grown to $12,232 — because each year's interest is calculated on a larger balance.

$20,000 for 20 years at different rates
RateFinal balanceInterest earnedMultiplier
4%$43,822$23,8222.19×
5%$53,066$33,0662.65×
6%$64,143$44,1433.21×
7%$77,394$57,3943.87×
8%$93,219$73,2194.66×
9%$112,088$92,0885.60×
10% ◀$134,550$114,5506.73×

Year-by-year projection

YearBalanceInterest this yearTotal interestGrowth
Year 1$22,000+$2,000$2,0001.10×
Year 2$24,200+$2,200$4,2001.21×
Year 3$26,620+$2,420$6,6201.33×
Year 4$29,282+$2,662$9,2821.46×
Year 5$32,210+$2,928$12,2101.61×
Year 6$35,431+$3,221$15,4311.77×
Year 7$38,974+$3,543$18,9741.95×
Year 8$42,872+$3,897$22,8722.14×
Year 9$47,159+$4,287$27,1592.36×
Year 10$51,875+$4,716$31,8752.59×
Year 11$57,062+$5,187$37,0622.85×
Year 12$62,769+$5,706$42,7693.14×
Year 13$69,045+$6,277$49,0453.45×
Year 14$75,950+$6,905$55,9503.80×
Year 15$83,545+$7,595$63,5454.18×
Year 16$91,899+$8,354$71,8994.59×
Year 17$101,089+$9,190$81,0895.05×
Year 18$111,198+$10,109$91,1985.56×
Year 19$122,318+$11,120$102,3186.12×
Year 20$134,550+$12,232$114,5506.73×

Growth chart

Balance growth over 20 years
$34k$67k$101k$135kYr1Yr5Yr10Yr15Yr20
Principal
Interest earned

Frequently asked questions

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