Pay rises don't count unless they show up as disposable income
A 20% pay rise is not 20% more usable money. Depending on what happens to your expenses, it is either much more than that or nothing at all.
7 min read
Here is a claim that sounds wrong and is not: the person earning $200,000 is not twice as well off as the person earning $100,000. They are potentially three times as well off, or not at all better off, and income alone cannot tell you which.
The number that decides it is disposable income (what's actually left over to save or invest): what you take home, minus what you spend. That is the only money that can become anything.
The worked example
| Person A | Person B | |
|---|---|---|
| Income | $100,000 | $200,000 |
| Expenses | $50,000 | $50,000 |
| Disposable income | $50,000 | $150,000 |
Twice the income. Three times the investable money. The mechanism is not complicated: expenses are subtracted from both, so holding them flat means the entire increase flows through to the bottom line, and the bottom line is a smaller number to start with.
Now do the version that actually happens. Person B's expenses rise to $150,000 because their lifestyle expanded with their income, exactly as the previous lesson described. Their disposable income (what's actually left over to save or invest) is $50,000. Identical to Person A's, on double the salary and considerably more hours and stress.
That is why income on its own answers nothing. It is one half of a subtraction.
The leverage runs both ways
The same arithmetic means expenses are a lever at least as powerful as income, and often more accessible.
Person A cuts spending from $50,000 to $45,000. That is a 10% reduction in expenses, but disposable income (what's actually left over to save or invest) goes from $50,000 to $55,000, a 10% increase. To achieve the same result through income, they would need about $7,300 of gross pay rise, because tax takes a cut of a raise and takes nothing from money you simply did not spend.
So $5,000 of expense reduction is worth about $7,300 of pay rise. Spending cuts are tax-free in a way that income is not.
Why a pay rise so often changes nothing
Three things happen to a raise before it reaches your disposable income (what's actually left over to save or invest), and only the third is optional.
Tax takes its share, and you cannot do anything about it. The working rule is that once you are past the tax-free threshold, roughly a third of a raise does not arrive. Someone on $80,000 given a $10,000 rise sees about $6,800 of it, once tax has come out, and less again if they are repaying HECS-HELP. That is not a trick and there is no lever attached to it. The site's Tax Calculator will give you the exact figure for your own situation if you want it.
Some of it is absorbed by genuine cost increases. Rent and prices rise with inflation (your money buying less over time), which ran at 3.8% in the year to June 2026.[1] A 3% pay rise in that environment is a small real-terms pay cut. This is unavoidable and is not lifestyle inflation, it is just the cost of the same life going up.
It helps to make that concrete rather than leave it as a percentage. Say your salary goes from $100,000 to $103,000, a 3% rise, in a year when inflation runs at 3.8%. On paper you earned $3,000 more. In practice, the things you buy cost 3.8% more, so the same shopping basket that cost you $100 last year now costs $103.80. Milk at $3.55 a bottle goes to about $3.68. Across a year of a $100,000 life, you needed roughly $3,800 more to stand still and you were given $3,000 before tax. That is a pay cut, printed on a letter congratulating you.
The rest gets absorbed by lifestyle inflation (your spending rising to match every pay rise), unless it is captured on the day it arrives.
The test
Six months after a pay rise, there is one question that tells you whether it happened.
Has the amount I invest each month gone up?
If yes, the rise was real and it is now working for you. If no, then whatever the letter said, your financial position is unchanged. You are doing the same work, for the same effective outcome, and the increase exists only on a payslip.
This is also the honest way to evaluate a job offer. A role paying $15,000 more, in a city where your rent is $12,000 higher, is a $3,000 job before you account for the commute, the hours, and what it costs you to be there. Compare offers on disposable income (what's actually left over to save or invest), not on headline salary.
Notes
- Australian Bureau of Statistics, CPI rose 3.8% in the year to June 2026. ↩
Check yourself
3 questions on this lesson. Nothing is recorded or sent anywhere.
1Person A earns $100,000 with $50,000 of expenses. Person B earns $200,000 with $50,000 of expenses. How do their disposable incomes compare?
Expenses are subtracted from both. Holding them flat means the whole increase flows to a bottom line that was much smaller to begin with.
2Why is $5,000 of expense reduction worth more than a $5,000 pay rise?
Spending cuts arrive untaxed. That said, expense reduction has a floor and income has no ceiling, so both levers matter.
3What single question does the lesson give for testing whether a pay rise was real?
If the investing figure is unchanged, your financial position is unchanged, whatever the letter said.