Simple Interest Calculator (2026)
Calculate simple interest on loans, investments or savings in AUD. Enter principal, rate and time to see results instantly.
I = P × (annual rate / 100) × yearsInputs
Starting amount, from $0 to $100 million
Annual interest rate as a percentage
From 0 to 100 years. Use 0.5 for six months.
$1,000.00
Total Amount
$11,000.00
Save and compare scenarios
Save up to five snapshots in this browser. They are not synced across devices. Shared links contain your inputs: anyone receiving the link can read them.
Indicative estimates based on the inputs shown and calculator assumptions at the time saved. Results may change when rules or methods are updated. General information only, not a quote, approval or recommendation. See the methodology and source notes on this page. CSV exports include their export timestamp.
Growth Over Time
How this estimate works
Interest applies only to the starting amount. For example, $10,000 at 5% a year for 2.5 years produces $1,250 interest and a $11,250 total. The chart ends at the duration entered, including part-years.
The amount and rate stay fixed throughout. This does not model mortgage repayments, changing balances, reinvested interest, fees or tax. A bank may use daily interest and product-specific payment rules. General information only, not a quote or recommendation.
If interest is reinvested, use the Compound Interest Calculator. Read the simple and compound interest comparison for the difference between the two models.
See ASIC Moneysmart on simple and compound interest. Last reviewed: 7 September 2026.
