Loan Calculator

About this calculator

This calculator shows what your regular repayment will be on a personal loan and how much of the total cost goes to interest. Enter the amount borrowed, the annual interest rate, and the term to see a full amortization schedule. Use the Compare alternative panel to weigh a different rate or term side by side.

How to read your results

The headline figure is your payment each period (monthly or fortnightly). Below it you'll see the total interest paid over the life of the loan and the total of all payments. The amortization schedule breaks every period into its interest and principal components, so you can see how the interest share shrinks as the balance falls. Early payments are mostly interest; later payments are mostly principal — this is normal for a level-payment loan.

How it's calculated

The calculator uses the standard level-payment amortization formula. The periodic payment M equals P times r times (1 + r) to the power of n, divided by ((1 + r) to the power of n minus 1), where P is the loan principal, r is the interest rate per period (the annual rate divided by the number of periods per year), and n is the total number of payments. For a monthly loan r is the annual rate divided by 12; for fortnightly it is divided by 26. When r is zero the formula degenerates and M is simply P divided by n. The amortization schedule is then built period by period: interest for each period is the remaining balance multiplied by r, the principal portion is M minus that interest, and the balance is reduced accordingly until it reaches zero on the final payment.

Worked example

Borrow 10,000 at 6% annual interest, repaid monthly over 3 years (36 payments).

The monthly payment is 304.22. Over 36 months you pay 10,951.90 in total, of which 951.89 is interest and 10,000 is the original principal.

Frequently asked questions

What is an amortizing loan?

An amortizing loan is repaid through equal periodic payments that cover both interest and a portion of the principal. Each payment reduces the outstanding balance until it reaches zero at the end of the term. Because the balance shrinks with every payment, the interest component of each payment falls over time and the principal component rises.

Why does fortnightly repayment save money compared with monthly?

Fortnightly payments are calculated using 26 periods a year (not 24), so you effectively make one extra monthly-equivalent payment each year. That extra payment reduces the principal faster, which means less interest accrues and the total interest cost over the life of the loan is lower.

What happens if the interest rate is 0%?

When the rate is zero the formula reduces to a simple division: each payment is the principal divided by the number of periods. No interest accrues, so the total of payments equals the amount borrowed.

Does this calculator account for fees or early-repayment charges?

No. The calculation is based on pure interest amortization. Real loans often carry origination fees, ongoing account fees, or break costs for early repayment that are not captured here. Treat the figures as a baseline and check your lender's terms for the full cost.

How does the Compare alternative panel work?

The Compare alternative panel lets you enter a different amount, rate, or term and see the resulting payment and total interest next to the base scenario. The delta rows show exactly how much more or less you would pay per period and over the full loan life.

Sources

• moneysmart.gov.au/loans/personal-loan-calculator
• www.investopedia.com/terms/a/amortization.asp
• www.consumerfinance.gov/about-us/blog/learn-how-amortization-affects-your-mortgage-payments

Reviewed by the YouCalc Team · Last reviewedJune 11, 2026