📈 Compound Interest
$20,000 at 5% for 30 Years
Investing $20,000 at 5% annual compound interest for 30 years grows to $86,439. That's $66,439 earned in interest on top of your original $20,000.
Compound Interest Calculator
Australia 2026
$
%
$
Total value after 30 years
$86,439
Amount invested$20,000
Interest earned$66,439
Interest multiplier4.32×
Year-by-year growth
| Year | Balance | Interest |
|---|---|---|
| Yr 1 | $21,000 | +$1,000 |
| Yr 2 | $22,050 | +$1,050 |
| Yr 3 | $23,153 | +$1,103 |
| Yr 4 | $24,310 | +$1,158 |
| Yr 5 | $25,526 | +$1,216 |
| Yr 6 | $26,802 | +$1,276 |
| Yr 7 | $28,142 | +$1,340 |
| Yr 8 | $29,549 | +$1,407 |
| Yr 9 | $31,027 | +$1,477 |
| Yr 10 | $32,578 | +$1,551 |
| Yr 11 | $34,207 | +$1,629 |
| Yr 12 | $35,917 | +$1,710 |
| Yr 13 | $37,713 | +$1,796 |
| Yr 14 | $39,599 | +$1,886 |
| Yr 15 | $41,579 | +$1,980 |
| Yr 16 | $43,657 | +$2,079 |
| Yr 17 | $45,840 | +$2,183 |
| Yr 18 | $48,132 | +$2,292 |
| Yr 19 | $50,539 | +$2,407 |
| Yr 20 | $53,066 | +$2,527 |
| Yr 21 | $55,719 | +$2,653 |
| Yr 22 | $58,505 | +$2,786 |
| Yr 23 | $61,430 | +$2,925 |
| Yr 24 | $64,502 | +$3,072 |
| Yr 25 | $67,727 | +$3,225 |
| Yr 26 | $71,113 | +$3,386 |
| Yr 27 | $74,669 | +$3,556 |
| Yr 28 | $78,403 | +$3,733 |
| Yr 29 | $82,323 | +$3,920 |
| Yr 30 | $86,439 | +$4,116 |
Final balance after 30 years
$86,439
Invested
$20,000
Interest earned
$66,439
Multiplier
4.32×
How $20,000 grows at 5%
Compound interest earns returns on your returns — not just your original investment. At 5% per year, your money doubles every 14.4 years (the Rule of 72). Over 30 years, that compounds to a 4.32× multiplier.
In year 1, $20,000 earns $1,000 in interest. By year 30, the annual interest has grown to $4,116 — because each year's interest is calculated on a larger balance.
Year-by-year projection
| Year | Balance | Interest this year | Total interest | Growth |
|---|---|---|---|---|
| Year 1 | $21,000 | +$1,000 | $1,000 | 1.05× |
| Year 2 | $22,050 | +$1,050 | $2,050 | 1.10× |
| Year 3 | $23,153 | +$1,103 | $3,153 | 1.16× |
| Year 4 | $24,310 | +$1,158 | $4,310 | 1.22× |
| Year 5 | $25,526 | +$1,216 | $5,526 | 1.28× |
| Year 6 | $26,802 | +$1,276 | $6,802 | 1.34× |
| Year 7 | $28,142 | +$1,340 | $8,142 | 1.41× |
| Year 8 | $29,549 | +$1,407 | $9,549 | 1.48× |
| Year 9 | $31,027 | +$1,477 | $11,027 | 1.55× |
| Year 10 | $32,578 | +$1,551 | $12,578 | 1.63× |
| Year 11 | $34,207 | +$1,629 | $14,207 | 1.71× |
| Year 12 | $35,917 | +$1,710 | $15,917 | 1.80× |
| Year 13 | $37,713 | +$1,796 | $17,713 | 1.89× |
| Year 14 | $39,599 | +$1,886 | $19,599 | 1.98× |
| Year 15 | $41,579 | +$1,980 | $21,579 | 2.08× |
| Year 16 | $43,657 | +$2,079 | $23,657 | 2.18× |
| Year 17 | $45,840 | +$2,183 | $25,840 | 2.29× |
| Year 18 | $48,132 | +$2,292 | $28,132 | 2.41× |
| Year 19 | $50,539 | +$2,407 | $30,539 | 2.53× |
| Year 20 | $53,066 | +$2,527 | $33,066 | 2.65× |
| Year 21 | $55,719 | +$2,653 | $35,719 | 2.79× |
| Year 22 | $58,505 | +$2,786 | $38,505 | 2.93× |
| Year 23 | $61,430 | +$2,925 | $41,430 | 3.07× |
| Year 24 | $64,502 | +$3,072 | $44,502 | 3.23× |
| Year 25 | $67,727 | +$3,225 | $47,727 | 3.39× |
| Year 26 | $71,113 | +$3,386 | $51,113 | 3.56× |
| Year 27 | $74,669 | +$3,556 | $54,669 | 3.73× |
| Year 28 | $78,403 | +$3,733 | $58,403 | 3.92× |
| Year 29 | $82,323 | +$3,920 | $62,323 | 4.12× |
| Year 30 | $86,439 | +$4,116 | $66,439 | 4.32× |
Growth chart
Balance growth over 30 years
Principal
Interest earned
Frequently asked questions
Explore other scenarios
$20,000 for 30 years — other rates
$20,000 at 5% — other time horizons
Related calculators
Compound Interest Calculator
Australia 2026
$
%
$
Total value after 30 years
$86,439
Amount invested$20,000
Interest earned$66,439
Interest multiplier4.32×
Year-by-year growth
| Year | Balance | Interest |
|---|---|---|
| Yr 1 | $21,000 | +$1,000 |
| Yr 2 | $22,050 | +$1,050 |
| Yr 3 | $23,153 | +$1,103 |
| Yr 4 | $24,310 | +$1,158 |
| Yr 5 | $25,526 | +$1,216 |
| Yr 6 | $26,802 | +$1,276 |
| Yr 7 | $28,142 | +$1,340 |
| Yr 8 | $29,549 | +$1,407 |
| Yr 9 | $31,027 | +$1,477 |
| Yr 10 | $32,578 | +$1,551 |
| Yr 11 | $34,207 | +$1,629 |
| Yr 12 | $35,917 | +$1,710 |
| Yr 13 | $37,713 | +$1,796 |
| Yr 14 | $39,599 | +$1,886 |
| Yr 15 | $41,579 | +$1,980 |
| Yr 16 | $43,657 | +$2,079 |
| Yr 17 | $45,840 | +$2,183 |
| Yr 18 | $48,132 | +$2,292 |
| Yr 19 | $50,539 | +$2,407 |
| Yr 20 | $53,066 | +$2,527 |
| Yr 21 | $55,719 | +$2,653 |
| Yr 22 | $58,505 | +$2,786 |
| Yr 23 | $61,430 | +$2,925 |
| Yr 24 | $64,502 | +$3,072 |
| Yr 25 | $67,727 | +$3,225 |
| Yr 26 | $71,113 | +$3,386 |
| Yr 27 | $74,669 | +$3,556 |
| Yr 28 | $78,403 | +$3,733 |
| Yr 29 | $82,323 | +$3,920 |
| Yr 30 | $86,439 | +$4,116 |