The best mortgage repayment calculator for Australians: compare up to nine free home loan scenarios and model rates, fees, offsets, extra repayments, and loan terms.
I've been a mortgage broker in Australia for over 23 years, and the same conversation kept repeating itself with clients. Someone would come in with a rate from one lender and a repayment figure from a bank's website, and neither number told them what they actually needed to know: what happens to my repayments if I add extra repayments, or use an offset account, or choose a 25 year term instead of 30. Most online calculators only ever show you one scenario at a time, so comparing options meant opening five different tabs, writing numbers down on paper, and hoping you didn't make a mistake along the way.
I wanted to solve that specific problem: give people a way to see multiple mortgage scenarios side by side, using the same assumptions, so the comparison is actually fair. That's why the calculator lets you build up to nine scenarios at once and compare rates, fees, offsets, extra repayments, and repayment frequencies in one place, in plain language, without pushing any particular lender or product.
The approach evolved a lot while building it. Early versions were much closer to a typical single-scenario calculator, and it was only after watching real clients get confused by jargon like "comparison rate" or "interest-only period" that I started rebuilding the interface around plain English explanations and a built-in glossary. I also made a deliberate choice to keep the assumptions visible rather than hidden, because I've seen how much trust borrowers lose when a number changes and they don't understand why. The goal was never to replace a conversation with a broker or lender, it was to give people a solid, honest starting point before they have that conversation.