How to read this
The first line is your repayment today on a standard principal-and-interest loan over the years you have left. Each line below shows the same loan at a higher rate. The middle column is the one that matters: the extra money that has to come from somewhere every month.
A variable-rate loan in Australia usually feels a rise within weeks. The lender changes the rate, writes to you, and your minimum repayment goes up from a set date. There is no fixed period to hide behind unless you fixed.
Why the extra is bigger than it looks
A repayment rise comes out of money you've already paid tax on. That's why the green box turns the yearly extra into a before-tax figure. A $2,000 a year rise isn't a $2,000 pay cut. For most people it's closer to $3,000.
What to do with the number
Write it down. It's the amount you need to find, cut or cover each month. The book works through where it usually comes from: the things you own and don't use, the rate you could ask your lender for, and the structure of your accounts. Start with the calculator that fits your situation.
If you're already paying more than the minimum, a rise may not change what leaves your account. Your lender recalculates the minimum, and if you already pay more than the new minimum, some lenders leave your repayment alone. You're still paying more interest, though. Less of each repayment comes off the loan.