Compound Interest Calculator
Updated on 1 Oct 2026 · Checked by Aotob
A$500 a month for 20 years grows to A$300,851 at 7%.
You put in A$130,000, including your A$10,000 start, and earn A$170,851 in growth. From year 17, growth is bigger than everything you put in.
Future value
A$300,851in 20 years
Your money more than doubles. Growth overtakes what you put in after year 16.
Show the working
FV = P(1+r)ⁿ + C × ((1+r)ⁿ − 1) ÷ r
P = 10,000C = 500r = 7% ÷ 12 = 0.005833n = 20 × 12 = 240
FV = 10,000 × 4.0387 + 500 × 520.93 = 40,387 + 260,463 = 300,851
How your A$300,851 builds up
Growth by year
| Year | Invested | Growth | Balance |
|---|---|---|---|
| 5 | 40,000 | 9,973 | 49,973 |
| 10 | 70,000 | 36,639 | 106,639 |
| 15 | 100,000 | 86,971 | 186,971 |
| 20 | 130,000 | 170,851 | 300,851 |
Questions people ask
Do Australian savings accounts compound monthly?
Most work out interest daily and pay it monthly. Choose Monthly for a close match to your bank.
Does this include tax on the interest?
Not by default. Interest is taxed at your marginal rate. Set your tax rate under Advanced options to see the growth after tax.
Updated 1 Oct 2026Source: compound interest formula (Moneysmart)Checked by AotobAn estimate, not financial adviceReport an issue