Tax return calculator: estimate your refund 2026-27

The ATO works out the tax you owe on your taxable income for the year, then subtracts the tax already withheld. A positive balance is a refund and a negative one is a bill.

Tax withheld comes from the income statements your employers finalise in myGov, plus any amounts a bank withheld because it didn't have your tax file number. PAYG instalments, paid by some investors and sole traders, count as well, so add them to the tax withheld figure.

The same steps sit behind the tax calculator for a full year of salary.

A bill usually means too little tax was withheld during the year. Withholding only knows about the job it comes from.

A second job often causes a bill. Take $40,000 from one employer and $28,000 from another in 2026-27. Tax and Medicare levy on $68,000 are $12,280.

Even when the second employer withholds at the no-tax-free-threshold rate, it treats $28,000 as your only income. It can't see that every dollar of it sits above $40,000.

Changing jobs mid-year is different. If the jobs don't overlap, each employer withholds as if its pay rate applied all year, so the tax-free threshold isn't counted twice.

Other common causes:

• Interest, dividends or rental profit with nothing withheld. In the default example, $500 of bank interest adds $160 of tax.
• A HELP debt your employer wasn't told about, so no HELP component was withheld.
• Income for surcharge purposes above the singles threshold without private hospital cover. It's $101,000 for 2025-26 and $105,000 for 2026-27.

A deduction cuts tax by your marginal rate, not by its full amount. In the default example, $1,200 of deductions saves $384, because each dollar was taxed at 30% plus the 2% Medicare levy.

From 2026-27, workers can claim a standard deduction of up to $1,000 for work-related expenses with no receipts, as the ATO's page on the standard deduction for work-related expenses (opens in a new tab) explains. The Treasury Laws Amendment (Tax Reform No. 1) Act 2026 made it law. Returns using it are first lodged from July 2027.

On the same $68,000 salary, the three cases compare like this.

Tax falls by $204 in 2026-27 even with a smaller deduction, because the 16% rate became 15% from 1 July 2026. Keeping receipts for the full $1,200 would cut tax by a further $64, because the extra $200 of deductions is worth 32 cents in the dollar. If withholding stayed at $11,200, the 2026-27 result would be a $760 bill.

Deductions only count if you paid the cost yourself, weren't reimbursed and can link it to earning your income. The rules, record-keeping and common claims are set out under tax deductions.