Your figures
Your payments and costs
All amounts in $. Use what you expect for the full 2026-27 year, not your best month. Yellow boxes are waiting for an entry.
$
Include GST if you charge it.
a year
$
Include GST if you are registered for GST.
Registered for GST?
Turnover under $5 million?
Under $5 million, you can claim the small business income tax offset.
$
Income outside the business. We assume your employer already withholds tax on any salary.
$
Private hospital cover?
$
Optional. A contribution you will claim as a tax deduction this year.
$
Lodged a return with this business income before?
%
Many people are told to put aside 30%. Change it to test your own rule.
Results
Where each payment goes
From one payment, what goes to the tax account and what is left for your costs and for you.
One payment, split up ($)
Payment and what is leftSet asideBusiness expenses
Things to know
What could change your buffer
Workings
How the year adds up
Your taxable income, the tax on it, and the GST you collect for the ATO.
About this calculator
Purpose. To estimate how much an Australian resident sole trader could move to a separate account from each payment, so that income tax, Medicare levy, any study loan repayment, GST and a planned personal super contribution are funded when they fall due.
Assumptions and why we chose them. You can change every assumption above.
- 2026-27 resident tax rates, the low income tax offset, the 2% Medicare levy, the Medicare levy surcharge tiers for singles and the HELP repayment rates, as published by the ATO. Rates as at , for the 2026-27 financial year. The 2026-27 Medicare low income thresholds were not yet published, so the 2025-26 thresholds are used.
- The example is a contractor paid 12,000 a month, registered for GST, with 36,000 of expenses and a HELP balance. It is the worked example we test the page against.
- The small business income tax offset is 16% of the tax on your business profit, up to 1,000. We work out that share of your tax by the share of your taxable income that comes from the business.
- Salary or other income is assumed to have the right tax withheld by your employer, so the buffer covers only the extra tax the business adds.
- GST on expenses is treated as fully claimable, and all expenses are treated as deductible in the year.
- The 30% comparison is the common rule of thumb, shown only as a check.
Limitations and their effect.
- It does not cover companies, trusts or partnerships, non-residents, capital gains, or businesses with employees. Employees add PAYG withholding and super guarantee, which would raise the amount to put aside.
- It does not model family Medicare levy thresholds, the family surcharge thresholds, or other offsets such as the senior and pensioner offset. These could lower the buffer for some people.
- It is not a PAYG instalment variation, a BAS or a tax return. Your actual instalment notices and assessment will differ, so reconcile each quarter.
- It assumes even income through the year. Seasonal or lumpy income means some payments need a larger share set aside than others.
- It does not include interest earned on the tax account, which is taxable.