GST & Tax calculator
BAS Set-Aside Calculator
Estimate a practical BAS set-aside from GST-inclusive sales, GST-creditable purchases, and an optional extra cash buffer.
Why use it
- Useful for setting cash aside during the quarter instead of guessing what BAS might require later.
- This is a planning estimate only. It does not replace BAS preparation, bookkeeping, or tax advice.
- The calculator assumes the entered purchases are GST-creditable and already GST-inclusive.
Calculator tool
Use the bas set-aside calculator
Estimate a practical BAS set-aside from GST-inclusive sales, GST-creditable purchases, and an optional extra cash buffer.
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Email it to yourself, send it to a customer, or copy the figures into a quote — all without an account.
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Important note
BizTools.au is designed to make business numbers easier to check, but calculator outputs still need judgment and real-world context.
- Calculator results are general estimates only and depend on the figures entered.
- Examples and summaries are provided for general information, not legal, tax, accounting, payroll, or financial advice.
- Before relying on a result for a real decision, check your assumptions and get qualified advice where needed.
How it works
Understand the formula before you use the result
The calculator uses a simple working formula so you can sense-check the result quickly and explain it clearly inside your business.
BAS set-aside formula
GST collected on sales = GST-inclusive sales ÷ 11
GST credits on purchases = GST-inclusive purchases ÷ 11
Net GST position = GST collected on sales - GST credits on purchases
Recommended set-aside = max(net GST position, 0) + additional cash buffer
If the net GST position is negative, the business may be in a credit position for GST. The calculator still shows the numbers, but that does not confirm a refund outcome.
Worked example
See the numbers in a realistic scenario
Use the example below as a sense check when you compare the calculator result to a real quote, sale, or pricing decision.
Worked example
Worked example: reserving cash for BAS
A small business has collected $22,000 in GST-inclusive sales, spent $5,500 on GST-inclusive business purchases, and wants to hold an extra $500 buffer.
- GST-inclusive sales: $22,000
- GST-inclusive purchases: $5,500
- Additional cash buffer: $500
Calculation steps
- GST collected on sales = $22,000 ÷ 11 = $2,000
- GST credits on purchases = $5,500 ÷ 11 = $500
- Net GST position = $2,000 - $500 = $1,500
- Recommended set-aside = $1,500 + $500 = $2,000
The business may want to reserve about $2,000 for the period, including the extra cash buffer.
FAQ
Common questions about the bas set-aside calculator
These are the practical questions operators usually run into when they apply the result to a real business decision.
Does this tell me exactly what my BAS will be?
No. It is only a cash-planning estimate. Actual BAS outcomes depend on bookkeeping quality, GST treatment, timing, and your full tax records.
What should I put in purchases?
Use GST-inclusive purchases or expenses that are likely to carry GST credits for the period you are planning. If a cost does not include GST or is not creditable, it should not be treated the same way.
Why add a cash buffer?
Many operators prefer to keep a little extra aside in case of timing differences, missed entries, or ordinary cashflow pressure around BAS time.
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