Free Shopify profit calculator for Australian ecommerce brands — ROAS, fees, LTV and 12-month forecasting

How do you calculate break-even ROAS?

Break-even ROAS is calculated by dividing 1 by your contribution margin. If your product has a 40% contribution margin after COGS, shipping and Shopify fees, your break-even ROAS is 1 ÷ 0.40 = 2.5x. Any campaign returning less than 2.5x revenue per dollar spent loses money on the first order.

The calculator works your contribution margin out from your real costs — including Shopify's Australian fees and GST — so the break-even ROAS it gives you is one you can actually hold Meta or Google to.

First-order vs LTV-adjusted break-even ROAS

First-order break-even ROAS assumes a customer only ever buys once. If customers come back, your true ceiling is lower: LTV-adjusted break-even ROAS = 1 ÷ (contribution margin × (1 + repeat orders per customer)). A store with a 50% margin and 0.5 repeat orders per customer breaks even at 1.33x instead of 2.0x.

That is why running ads below first-order break-even can be rational — but only when your repeat rate genuinely supports it. The calculator computes both numbers from your repeat-purchase input, so the decision is made with arithmetic instead of optimism.

Worked example: an $80 AOV Australian skincare brand

Here is one order run through every formula on this page, for a GST-registered store on the Shopify Basic plan taking a domestic card payment.

Notice the two break-even ROAS numbers. Meta reports your revenue GST-inclusive, so the target you hold your ad account to is 2.13x — not the 1.94x your ex-GST spreadsheet suggests. Missing that 10% wedge is one of the most common ways Australian stores quietly scale at a loss.

What does Shopify actually take per sale in Australia?

In Australia, Shopify takes 1.75% + A$0.30 per domestic card sale on the Basic plan (1.6% on Grow, 1.4% on Advanced), plus 10% GST on the processing fee. On a A$100 sale that is A$2.26 including GST, leaving a net payout of A$97.74 — verified against shopify.com/au/pricing, July 2026.

If you are GST-registered, the GST on that fee comes back as an input tax credit, so the true cost is A$2.05. Amex and international cards cost more: 2.9% / 2.8% / 2.7% + 30¢ for Amex and 3.5% / 3.4% / 3.3% + 30¢ for international cards on Basic / Grow / Advanced — worth checking before you scale international ad spend.

How does GST change your Shopify profit maths?

Yes, Shopify charges GST in Australia — but asymmetrically. Shopify adds 10% GST to subscription bills unless you add a GST-registered ABN to your store. Shopify Payments processing fees always carry 10% GST regardless of ABN, though GST-registered merchants claim it back as an input tax credit on their BAS.

Should you model GST-inclusive or GST-exclusive prices?

Model profit on ex-GST revenue: divide your GST-inclusive AOV by 1.1 before subtracting costs. The GST you collect at checkout was never yours — it belongs to the ATO. Ad platforms report GST-inclusive revenue, which silently inflates ROAS by 10% if you don't correct for it. The calculator handles this conversion for you.

When do you have to register for GST?

Registration is mandatory once your GST turnover reaches A$75,000 in a rolling 12 months — you have 21 days to register after crossing it (ATO). Below the threshold registration is optional, but registering lets you claim GST credits on your inputs, including ad spend and Shopify fees.

Can you claim GST back on Meta ads and Shopify fees?

Yes. Meta and Google both charge 10% GST on Australian ad invoices, and Shopify Payments fees carry GST too — all claimable as input tax credits if you are GST-registered. Shopify issues monthly invoices showing the GST paid on transaction fees (Settings → Payments → View payouts → Documents). Speak to your accountant about your specific position.

Shopify Payments vs PayPal vs Afterpay: which fees hurt most?

*Shopify's third-party payment provider fee (2% Basic, 1% Grow, 0.6% Advanced) is waived when Shopify Payments is your primary gateway. Rates verified July 2026; PayPal's February 2026 schedule.

Buy-now-pay-later is the quiet margin killer: a 5% Afterpay commission on a store otherwise paying 1.75% nearly triples the payment line on those orders. If a large share of your checkout is BNPL, model your blended payment rate — the calculator's payment-fee input takes whatever blend you actually run.

Should you upgrade your Shopify plan to save on fees?

There is a clean crossover point: Grow costs A$93/month more than Basic but saves 0.15% on every card sale, so it pays for itself above roughly A$62,000/month in card revenue. Advanced costs A$426/month more than Grow and saves a further 0.2%, breaking even around A$213,000/month. Below those lines, the cheaper plan wins on fees alone — upgrade for features, not rates.

MER vs ROAS: which should you track?

MER (marketing efficiency ratio) is total revenue divided by total ad spend across every channel. Platform ROAS relies on each platform's own attribution, which routinely over-credits itself — Meta and Google can both claim the same sale. MER can't be gamed that way, which is why it belongs in your board reporting while ROAS stays at campaign level.

Healthy DTC brands typically run a MER between 3 and 5. It scales with size: brands doing $1–5m a year often sit at 1.5–2.5x while $25m+ brands push 3.5–6x (Eightx, 2026). The calculator reports MER alongside ROAS so you can see both stories at once.

Australian ecommerce benchmarks (2026)

Use these published, named-source figures to sanity-check the numbers you type into the calculator — and to judge the outputs it hands back.

Benchmarks are medians or averages from the named public sources — your category and price point move the goalposts. That is exactly why the calculator grades your numbers instead of comparing you to one global average.

Why fixed costs stay out of break-even ROAS

Break-even ROAS is a per-order number, so it only contains costs that scale with each order: product, shipping, payment fees, returns. Your Shopify subscription, apps and agency retainer don't belong in it — stuffing them in makes every campaign look unprofitable and leads to underspending. Fixed costs re-enter the picture at the account level, through MER and the monthly profit line, which is exactly where the calculator applies them.

How the 12-month forecast works

Most ecommerce forecasts are a straight line drawn through hope. This one models the three forces that actually shape year one: your ad spend ramping month on month, your ROAS softening as you scale into colder audiences (you choose how hard the drag is), and repeat customers stacking — every month's new customers keep buying across the following twelve. That is why the profit curve bends instead of climbing forever, and why the forecast shows your efficient ceiling instead of flattering you.

How this compares to other profit calculators

Shopify's official calculator is a simple margin/markup tool — no fees, no tax, no ad economics. Most break-even ROAS calculators stop at the one formula. This page combines Australian fees, GST, ROAS, MER, LTV and forecasting in one place, which is the whole point.

Built and maintained by Hey Sage, an Australian ecommerce advertising agency. All Shopify Australia rates on this page verified against shopify.com/au/pricing in July 2026. Last updated 11 July 2026. This page is general information, not tax or financial advice.