2026-11-05

Free GST, markup, break-even and card fee calculators for Australian small businesses

We've put four free calculators for Australian small businesses on one page. Add or take out GST, turn a markup into a margin, find your break-even point, and see what card fees cost you now that you can't add a surcharge for eftpos, Mastercard or Visa. Everything is in A$, it runs in your browser, and your numbers are never stored or sent.

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GST: divide by 11 to take it out

GST is 10% on most goods and services. To add it, multiply the price without GST by 1.1. To find the GST inside a price, divide by 11: A$110 includes A$10 of GST. The calculator rounds the GST to the nearest cent, with half a cent rounding up, which is what the ATO's tax invoice guidance says for an invoice with one item.

What it can't decide for you is whether to charge GST at all. GST applies to your sales if you're registered for GST, or required to be, and you must register within 21 days of your GST turnover reaching A$75,000 a year (A$150,000 for non-profits). The ATO's Registering for GST page has the details.

Markup isn't margin

Buy something for A$10 and sell it for A$15, and the A$5 profit is a 50% markup but only a 33.33% margin. Mixing the two up is an easy way to underprice: if you want a 40% margin, a 40% markup won't get you there, because it gives 28.57%. The calculator works from your markup, from the margin you want, or from the price you already charge.

Buying stock from overseas? Pick the currency and the page fetches that day's rate from exchange-api, a free and open rates dataset, and shows the date of the rate. It only fetches when you pick a currency, and if the rate can't load, or your bank gives you a different one, you can type your own.

Break-even: how many sales cover your costs

Type your fixed costs for the month, your price, and what each item costs you. If rent, wages and software come to A$6,000 a month and each A$25 sale costs you A$10, each sale covers A$15, so you break even at 400 sales, or A$10,000. Add a profit target and it shows how many more you need. If an item costs as much as you sell it for, it tells you plainly: no number of sales will break even.

Card fees, now that surcharges have ended

Since 1 October 2026, Australian businesses can't add a surcharge for paying by eftpos, Mastercard or Visa (RBA, Small Business Ombudsman). Your payment provider still charges its merchant fee, so it now comes out of your takings unless your prices cover it.

The card fee calculator takes your monthly card sales and your own fee, from your merchant statement or your payment provider's dashboard, or splits it by card type with your own rates. It shows what fees cost you a month and a year, and the price rise that would cover them: the fee ÷ (1 − the fee). At a 1.5% fee that's 1.52%, a little more than the fee because the fee is charged on the higher price too. A coffee at A$4.50 becomes A$4.57.

Raising prices is allowed, as long as the new price is clear before purchase and you don't mislead customers about the reason for the increase. Public holiday surcharges are still allowed if they're clearly shown, and our free Christmas public holiday surcharge wording covers each state.

Is the old surcharge wording still up?

When we checked thousands of small-business websites, terms pages, PDF menus and old menu pages were where the old surcharge wording most often sat. The free surcharge check reads your website and PDF menus and lists every mention.

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