📈 Compound Interest

$5,000 at 8% for 30 Years

Investing $5,000 at 8% annual compound interest for 30 years grows to $50,313. That's $45,313 earned in interest on top of your original $5,000.

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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%
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Total value after 30 years
$50,313
Amount invested$5,000
Interest earned$45,313
Interest multiplier10.06×
Year-by-year growth
YearBalanceInterest
Yr 1$5,400+$400
Yr 2$5,832+$432
Yr 3$6,299+$467
Yr 4$6,802+$504
Yr 5$7,347+$544
Yr 6$7,934+$588
Yr 7$8,569+$635
Yr 8$9,255+$686
Yr 9$9,995+$740
Yr 10$10,795+$800
Yr 11$11,658+$864
Yr 12$12,591+$933
Yr 13$13,598+$1,007
Yr 14$14,686+$1,088
Yr 15$15,861+$1,175
Yr 16$17,130+$1,269
Yr 17$18,500+$1,370
Yr 18$19,980+$1,480
Yr 19$21,579+$1,598
Yr 20$23,305+$1,726
Yr 21$25,169+$1,864
Yr 22$27,183+$2,014
Yr 23$29,357+$2,175
Yr 24$31,706+$2,349
Yr 25$34,242+$2,536
Yr 26$36,982+$2,739
Yr 27$39,940+$2,959
Yr 28$43,136+$3,195
Yr 29$46,586+$3,451
Yr 30$50,313+$3,727
Final balance after 30 years
$50,313
Invested
$5,000
Interest earned
$45,313
Multiplier
10.06×

How $5,000 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 30 years, that compounds to a 10.06× multiplier.

In year 1, $5,000 earns $400 in interest. By year 30, the annual interest has grown to $3,727 — 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.

$5,000 for 30 years at different rates
RateFinal balanceInterest earnedMultiplier
4%$16,217$11,2173.24×
5%$21,610$16,6104.32×
6%$28,717$23,7175.74×
7%$38,061$33,0617.61×
8% ◀$50,313$45,31310.06×
9%$66,338$61,33813.27×
10%$87,247$82,24717.45×

Year-by-year projection

YearBalanceInterest this yearTotal interestGrowth
Year 1$5,400+$400$4001.08×
Year 2$5,832+$432$8321.17×
Year 3$6,299+$467$1,2991.26×
Year 4$6,802+$504$1,8021.36×
Year 5$7,347+$544$2,3471.47×
Year 6$7,934+$588$2,9341.59×
Year 7$8,569+$635$3,5691.71×
Year 8$9,255+$686$4,2551.85×
Year 9$9,995+$740$4,9952.00×
Year 10$10,795+$800$5,7952.16×
Year 11$11,658+$864$6,6582.33×
Year 12$12,591+$933$7,5912.52×
Year 13$13,598+$1,007$8,5982.72×
Year 14$14,686+$1,088$9,6862.94×
Year 15$15,861+$1,175$10,8613.17×
Year 16$17,130+$1,269$12,1303.43×
Year 17$18,500+$1,370$13,5003.70×
Year 18$19,980+$1,480$14,9804.00×
Year 19$21,579+$1,598$16,5794.32×
Year 20$23,305+$1,726$18,3054.66×
Year 21$25,169+$1,864$20,1695.03×
Year 22$27,183+$2,014$22,1835.44×
Year 23$29,357+$2,175$24,3575.87×
Year 24$31,706+$2,349$26,7066.34×
Year 25$34,242+$2,536$29,2426.85×
Year 26$36,982+$2,739$31,9827.40×
Year 27$39,940+$2,959$34,9407.99×
Year 28$43,136+$3,195$38,1368.63×
Year 29$46,586+$3,451$41,5869.32×
Year 30$50,313+$3,727$45,31310.06×

Growth chart

Balance growth over 30 years
$13k$25k$38k$50kYr1Yr5Yr10Yr15Yr20Yr25Yr30
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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