Compound Interest Calculator
See how much your savings could grow with compound interest and regular deposits, year by year.
Deposits are added at the end of each month. Interest is before tax. Interest earned in a bank account is taxable income.
| Year | Deposits to date | Interest to date | Balance |
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Printed from ClearCalc (clearcalc.com.au/interest-calculator/). Estimates only, not financial advice.
Compound vs simple interest
Simple interest is paid only on the money you put in. $10,000 at 5% earns $500 every year, so $5,000 over 10 years.
Compound interest is also paid on interest you've already earned, so your balance grows faster each year. The same $10,000 at 5%, compounded monthly, grows to about $16,470 in 10 years. That's about $6,470 in interest, roughly $1,470 more than simple interest.
The formula
For a single deposit, the compound interest formula is A = P × (1 + r/n)n×t, where P is the starting amount, r is the yearly rate as a decimal, n is how many times a year interest is added, and t is the number of years. The calculator also adds your monthly deposits and works month by month.
How to grow your savings faster
- Start early. Time matters more than anything else with compounding.
- Add regularly. Even $50 a week makes a large difference over 10 years or more.
- Chase the rate, but read the conditions. Many high-interest savings accounts only pay their top rate if you deposit a set amount each month or make no withdrawals. Others offer a high rate for the first few months only.
- Remember tax. Interest is added to your taxable income, so you'll keep less than the headline rate at higher tax brackets.
In October 2026, ongoing savings rates with no conditions were around 5% at competitive banks, with introductory rates up to about 6%.
Frequently asked questions
How much will $10,000 earn in a year?
At 5% p.a. with interest added monthly, $10,000 earns about $512 in a year, slightly more than the $500 from simple interest.
What's the difference between daily and monthly compounding?
Most Australian savings accounts calculate interest daily and pay it monthly. The difference between daily and monthly compounding is small, only a few dollars a year on $10,000.
How long does it take to double my money?
Use the rule of 72: divide 72 by the interest rate. At 5%, money doubles in about 14.4 years. At 6%, about 12 years.
Is interest on savings taxed in Australia?
Yes. Interest is assessable income and is taxed at your marginal rate. Your bank reports it to the ATO, and it's usually pre-filled in your tax return.
Last reviewed October 2026. This calculator gives an estimate for general information only. Check important figures with the relevant government agency or a licensed professional.