BAS Calculator (GST Worksheet)
Estimate the GST on your business activity statement: 1A GST on sales, 1B GST on purchases, and the net amount to pay or claim back.
This estimates the GST section of a BAS only. It is not a lodgement, and it does not cover PAYG withholding, PAYG instalments or other BAS items. Check the figures against your accounting records or ask a registered tax or BAS agent.
GST for one reporting period
Enter amounts including GST for the period. Leave a box empty if it does not apply. The figures shown are an example; replace them with your own.
More amounts: G4, G13, G14 and G15
How the calculator works
It follows the ATO’s calculation worksheet method for the full BAS. Everything you enter includes GST, and the GST is one eleventh of the amounts that are subject to GST.
Sales: G6 = G1 − (G2 + G3 + G4). Then 1A = G6 ÷ 11.
Purchases: G17 = (G10 + G11) − (G13 + G14 + G15). Then 1B = G17 ÷ 11.
Net GST = 1A − 1B
| Label | What it is | Where it is used |
|---|---|---|
| G1 | Total sales, including GST: taxable, GST-free and input-taxed | Reported on the BAS |
| G2 | Export sales: GST-free exports (also in G1) | Worksheet; reported on a full BAS |
| G3 | Other GST-free sales (also in G1) | Worksheet; reported on a full BAS |
| G4 | Input-taxed sales (also in G1) | Your records only |
| 1A | GST on sales: G6 ÷ 11 | Reported on the BAS |
| G10 | Capital purchases, including GST | Reported on a full BAS |
| G11 | Non-capital purchases, including GST | Reported on a full BAS |
| G13 | Purchases for making input-taxed sales (also in G10 or G11) | Your records only |
| G14 | Purchases without GST in the price (also in G10 or G11) | Your records only |
| G15 | Estimated private or non-deductible purchases (also in G10 or G11) | Your records only |
| 1B | GST on purchases: G17 ÷ 11 | Reported on the BAS |
Amounts at G4, G13, G14 and G15 are not lodged, but the ATO says to keep them in your records because they are used to work out 1A and 1B. Adjustments (G7 and G18) are not included in this calculator.
Worked examples
Example 1: GST to pay
In the quarter, total sales including GST (G1) were $66,000.00. Of those, $5,500.00 were exports (G2) and $4,400.00 were other GST-free sales (G3). G2 + G3 + G4 is $9,900.00, so the sales subject to GST (G6) are $66,000.00 − $9,900.00 = $56,100.00. 1A = $56,100.00 ÷ 11 = $5,100.
Capital purchases (G10) were $11,000.00 and non-capital purchases (G11) were $27,500.00, a total of $38,500.00. 1B = $38,500.00 ÷ 11 = $3,500.
Net GST = $5,100 − $3,500 = $1,600 to pay. These are the starting figures in the calculator.
Example 2: some purchases had no GST in the price
Say $5,500.00 of the $38,500.00 of purchases had no GST in the price (G14). The purchases subject to GST (G17) are $38,500.00 − $5,500.00 = $33,000.00 and 1B = $33,000.00 ÷ 11 = $3,000. Net GST = $5,100 − $3,000 = $2,100 to pay.
Example 3: a GST refund
Sales of $11,000.00, all taxable, give 1A = $11,000.00 ÷ 11 = $1,000. Purchases of $33,000.00, all with GST in the price, give 1B = $33,000.00 ÷ 11 = $3,000. Net GST = $1,000 − $3,000 = −$2,000, a refund of $2,000.
Example 4: rounding
If the only figure is G1 = $12,345.67 and all of it is taxable, 1A = $12,345.67 ÷ 11 = $1,122.33. The BAS takes whole dollars, so you would report $1,122.
Simpler BAS
Businesses with a GST turnover of less than $10 million generally report GST using Simpler BAS, the ATO’s default method. You report only three GST figures, G1 total sales, 1A GST on sales and 1B GST on purchases, and you do not complete a calculation worksheet. The full reporting method, with G2, G3, G10 and G11 as well, applies from a GST turnover of $10 million.
Simpler BAS businesses take 1A and 1B from their accounting records (the accounts method), not from the worksheet this calculator follows. It can still give a rough check on those two figures: put your GST-free sales in G3 and all purchases in G11, then compare 1A and 1B with your records. Your records are the source for what you lodge.
Rounding, timing and records
- Whole dollars. For a BAS the ATO says to round down to whole dollars, not show cents, and not round up to the next dollar. The calculator rounds 1A and 1B down and shows the figure before rounding down. The calculation uses the exact amounts you enter, so a $1 difference from your own workings is possible if you round each label first.
- Which period. On a cash basis, GST on a sale goes in the period you are paid and the credit on a purchase goes in the period you pay. On a non-cash basis, it goes in the period of the invoice or the payment, whichever comes first. Your GST accounting method decides this.
- Tax invoices. For purchases over $82.50 (including GST), hold a tax invoice before you claim the GST credit.
- Records. Keep tax invoices and other GST records for 5 years from when the record was made or the transaction was completed, whichever is later.
Frequently asked questions
What are 1A and 1B on a BAS?
1A is the GST on your sales, the GST you owe. 1B is the GST on your purchases, the GST credits you claim. The difference is your net GST for the period. If 1A is more than 1B you pay the difference. If 1B is more than 1A you are due a refund.
Should the amounts I enter include GST?
Yes. With the ATO’s calculation worksheet method, the amounts at every label must include GST, and you mark “Yes” in the box under G1 to say so. This calculator follows that method, so enter GST-inclusive figures. If you take 1A and 1B straight from accounting records instead (the accounts method), the ATO lets you choose to report G1 with or without GST, but you must then use the same choice at the other labels.
What goes in G10 and what goes in G11?
G10 is capital purchases such as machinery, cash registers, computers, cars and land and buildings. G11 is everything else you bought for the business, such as trading stock, stationery and repairs. If you do not record the two separately and your GST turnover is expected to be under $1 million, the ATO says you can put capital items costing more than $1,000 at G10 and items costing $1,000 or less at G11.
What counts as a purchase without GST in the price (G14)?
Purchases that did not have GST in the price. The ATO lists GST-free and input-taxed purchases, purchases from a supplier that is not registered for GST, purchases not connected with Australia, and Australian taxes, fees and charges where GST was not included in the price. These amounts are part of G10 or G11, so they are entered there first and then taken out again at G14. There is no GST in them to claim as a credit.
Do I report cents on the BAS?
No. The ATO says to round down to whole dollars and not show cents, and not to round up to the next dollar. The calculator does this for 1A and 1B and shows the amount before rounding down underneath.
I use Simpler BAS. Do I need G2, G3, G10 and G11?
No. On Simpler BAS you report only G1, 1A and 1B, and you take 1A and 1B from your accounting records (the ATO’s accounts method) rather than a worksheet. This calculator follows the worksheet, so use it as a rough check on those two figures: put GST-free sales in G3 so they are left out of 1A, and put all purchases in G11.
Is this the amount I will have to pay the ATO?
No, it is an estimate of the GST section only. It leaves out adjustments (G7 and G18), PAYG withholding, PAYG instalments and any other amounts on your statement, and it depends on how accurate the figures you enter are. Your lodged BAS and the ATO’s assessment decide what you owe.
Sources
- ATO: Complete your BAS (rounding down to whole dollars)
- ATO: Choose a method to complete your BAS (calculation worksheet method and accounts method)
- ATO: Step 1, sales (G1, G2, G3)
- ATO: Step 2, calculating sales using the calculation worksheet (G4 to G9 and 1A)
- ATO: Step 3, purchases (G10, G11)
- ATO: Step 4, calculating purchases using the calculation worksheet (G12 to G20 and 1B)
- ATO: GST reporting methods (Simpler BAS and full reporting)
- ATO: BAS and GST tips (whole dollars, tax invoices, record keeping)
General information only, not tax advice. For your own BAS, use the ATO’s instructions or a registered tax or BAS agent.