📈 Compound Interest
$20,000 at 5% for 15 Years
Investing $20,000 at 5% annual compound interest for 15 years grows to $41,579. That's $21,579 earned in interest on top of your original $20,000.
Compound Interest Calculator
Australia 2026
$
%
$
Total value after 15 years
$41,579
Amount invested$20,000
Interest earned$21,579
Interest multiplier2.08×
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 |
Final balance after 15 years
$41,579
Invested
$20,000
Interest earned
$21,579
Multiplier
2.08×
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 15 years, that compounds to a 2.08× multiplier.
In year 1, $20,000 earns $1,000 in interest. By year 15, the annual interest has grown to $1,980 — 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× |
Growth chart
Balance growth over 15 years
Principal
Interest earned
Frequently asked questions
Explore other scenarios
$20,000 for 15 years — other rates
$20,000 at 5% — other time horizons
Related calculators
Compound Interest Calculator
Australia 2026
$
%
$
Total value after 15 years
$41,579
Amount invested$20,000
Interest earned$21,579
Interest multiplier2.08×
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 |