📈 Compound Interest

$1,000 at 8% for 25 Years

Investing $1,000 at 8% annual compound interest for 25 years grows to $6,848. That's $5,848 earned in interest on top of your original $1,000.

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
$
%
$
Total value after 25 years
$6,848
Amount invested$1,000
Interest earned$5,848
Interest multiplier6.85×
Year-by-year growth
YearBalanceInterest
Yr 1$1,080+$80
Yr 2$1,166+$86
Yr 3$1,260+$93
Yr 4$1,360+$101
Yr 5$1,469+$109
Yr 6$1,587+$118
Yr 7$1,714+$127
Yr 8$1,851+$137
Yr 9$1,999+$148
Yr 10$2,159+$160
Yr 11$2,332+$173
Yr 12$2,518+$187
Yr 13$2,720+$201
Yr 14$2,937+$218
Yr 15$3,172+$235
Yr 16$3,426+$254
Yr 17$3,700+$274
Yr 18$3,996+$296
Yr 19$4,316+$320
Yr 20$4,661+$345
Yr 21$5,034+$373
Yr 22$5,437+$403
Yr 23$5,871+$435
Yr 24$6,341+$470
Yr 25$6,848+$507
Final balance after 25 years
$6,848
Invested
$1,000
Interest earned
$5,848
Multiplier
6.85×

How $1,000 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 25 years, that compounds to a 6.85× multiplier.

In year 1, $1,000 earns $80 in interest. By year 25, the annual interest has grown to $507 — 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.

$1,000 for 25 years at different rates
RateFinal balanceInterest earnedMultiplier
4%$2,666$1,6662.67×
5%$3,386$2,3863.39×
6%$4,292$3,2924.29×
7%$5,427$4,4275.43×
8% ◀$6,848$5,8486.85×
9%$8,623$7,6238.62×
10%$10,835$9,83510.83×

Year-by-year projection

YearBalanceInterest this yearTotal interestGrowth
Year 1$1,080+$80$801.08×
Year 2$1,166+$86$1661.17×
Year 3$1,260+$93$2601.26×
Year 4$1,360+$101$3601.36×
Year 5$1,469+$109$4691.47×
Year 6$1,587+$118$5871.59×
Year 7$1,714+$127$7141.71×
Year 8$1,851+$137$8511.85×
Year 9$1,999+$148$9992.00×
Year 10$2,159+$160$1,1592.16×
Year 11$2,332+$173$1,3322.33×
Year 12$2,518+$187$1,5182.52×
Year 13$2,720+$201$1,7202.72×
Year 14$2,937+$218$1,9372.94×
Year 15$3,172+$235$2,1723.17×
Year 16$3,426+$254$2,4263.43×
Year 17$3,700+$274$2,7003.70×
Year 18$3,996+$296$2,9964.00×
Year 19$4,316+$320$3,3164.32×
Year 20$4,661+$345$3,6614.66×
Year 21$5,034+$373$4,0345.03×
Year 22$5,437+$403$4,4375.44×
Year 23$5,871+$435$4,8715.87×
Year 24$6,341+$470$5,3416.34×
Year 25$6,848+$507$5,8486.85×

Growth chart

Balance growth over 25 years
$2k$3k$5k$7kYr1Yr5Yr10Yr15Yr20Yr25
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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