How this calculator works

A tax refund is not a bonus. It is the difference between the tax, levies and compulsory study-loan repayments assessed on your taxable income, and the tax already withheld from your pay, plus any other credits that form part of the assessment. If those credits are larger than the amount payable, the Australian Taxation Office (ATO) usually refunds the difference. If they are smaller, you receive a tax bill.

The Never Lose Interest tax refund estimator applies official resident income tax rates for 2025-26 and 2026-27, the low income tax offset, the Medicare levy, the Medicare levy surcharge where it applies, and, if you choose, the official HELP repayment, then subtracts the PAYG withheld figure you enter. It is a planning illustration. It is not a myTax estimate, and it is not a notice of assessment.

For how to lodge, see how to lodge your tax return. For official processing times, which are not a single number, see how long a tax refund takes.

This is general information only. It is not personal tax advice.

The arithmetic

In outline:

Estimated refund or bill = (PAYG withheld + other credits you enter) minus (income tax after LITO + Medicare levy + Medicare levy surcharge + compulsory HELP repayment)

Income tax is calculated on the taxable income you type in, using the official resident rates explained in the income tax calculator guide. The low income tax offset reduces that tax, but not below zero. The 2% Medicare levy is then added, with the published low-income reduction where it applies. If you do not have appropriate private patient hospital cover and your income is above the surcharge thresholds, the Medicare levy surcharge is added as well. See Medicare levy and surcharge.

If you have a HELP or other study and training support loan, a compulsory repayment can be included. That repayment is part of the assessment and can turn an otherwise small refund into a bill, or a nil balance into an amount still owing. The official 2026-27 repayment at $80,000 of repayment income is $1,570.80, as used in the HELP repayment calculator.

PAYG withholding is the tax already taken from salary, wages or other payments during the year. You will usually find the year-to-date figure on your income statement in ATO online services, once your employer has marked it tax ready.

The optional "other credits" box is only for a figure you have already calculated elsewhere, such as a refundable offset. The estimator does not work out franking credits for you.

A documented worked example

The official 2026-27 figures for a resident with $80,000 of taxable income and appropriate private patient hospital cover, already checked in the income tax calculator tests, are:

  • income tax of $14,520
  • no low income tax offset
  • a Medicare levy of $1,600
  • tax and levy payable of $16,120

If PAYG withheld is also $16,120, the estimated balance is nil. If $20,000 has been withheld, the estimated refund is $3,880. If only $10,000 has been withheld, the estimated bill is $6,120.

If that same person also has a HELP loan, and repayment income is the same $80,000, the official compulsory repayment of $1,570.80 is added. Payable becomes $17,690.80. With $16,120 withheld, the estimated bill is $1,570.80.

A second official 2026-27 case is $45,000 of taxable income, with hospital cover: income tax of $4,020, a low income tax offset of $325, a Medicare levy of $900, and tax and levy of $4,595. If $5,000 has been withheld, the estimated refund is $405.

These withholding figures are documented assumptions, used so you can check the arithmetic. They are not official ATO refund examples, and they are not a prediction of what any employer will withhold.

What the estimator leaves out

The tool does not:

  • estimate deductions, or apply the $1,000 standard deduction proposed for later years, except to the extent you have already subtracted deductions from the taxable income you enter
  • include every offset, such as the seniors and pensioners tax offset beyond the option in the form, spouse offsets, or a franking credit refund
  • use foreign-resident rates, or part-year residency
  • know whether the ATO will apply your refund to a tax debt, a HELP balance in a different way, or a debt you have with another government agency
  • tell you how long the refund will take once you lodge

The myTax estimate you see just before you lodge is also an estimate. The ATO says the final balance on your notice of assessment may differ. For 2026-27, the 2% Medicare levy is official, but a separate official table of 2026-27 low-income levy-reduction thresholds had not been published as at mid-November 2026. The estimator uses the published 2025-26 thresholds for that reduction and flags that on the result.

Frequently asked questions

Why is my refund smaller than last year if my pay is similar?

The ATO notes that a refund is smaller when the tax withheld during the year was closer to the tax assessed, and that a credit can also be offset against another debt. Rate changes, deductions, HELP, and the Medicare levy surcharge can all move the result. Compare the assessment, not only the refund.

Does a refund mean I planned well?

Not necessarily. A large refund often means too much tax was withheld during the year, so you made an interest-free loan to the ATO. A bill means too little was withheld. Neither result, on its own, says whether your deductions were correct.

Can I use this instead of myTax?

No. Lodge through myTax, a registered tax agent, or a paper return, using your pre-filled income statement and records. Use this tool only to understand the arithmetic before you lodge.

General information warning

This article is general information only. It is not personal financial product advice or tax advice, and it is not a tax assessment. It does not take into account your objectives, financial situation or needs. Confirm the current rates and your income statement with the ATO, and consider speaking with a registered tax agent, before you lodge or rely on an estimate.

Sources

Last reviewed: November 2026.