A high ROAS does not always mean profit. Calculate what ads must return after deducting VAT, commissions, shipping and returns.
Net Revenue = Selling Price ÷ (1 + VAT % ÷ 100)Gross order value collected from the customer minus consumption taxes remitted directly to tax authorities.
Contribution = Net Revenue − COGS − Shipping − Fees − Returns − Variable CostsPer-order cash left over after fulfilling the sale, available to cover customer acquisition costs and net profit.
Max CPA = Contribution ÷ (1 + Ad Tax % ÷ 100)The absolute ceiling you can pay an ad network to acquire one order without losing money on that transaction.
Break-Even ROAS = Reported Revenue Basis ÷ Max CPAThe floor ROAS below which every ad dollar burns equity. Calculated against gross or net revenue depending on how your pixel tracks.
Target CPA = (Contribution − Net Revenue × Target Margin %) ÷ (1 + Ad Tax %)Allowable acquisition cost and corresponding ROAS after reserving your desired net profit per order.
An order of $1,200 with 20% VAT, $450 unit product cost, $60 delivery, and 12% combined marketplace and card processing fees.
Break-even ROAS is the minimum ad return required to cover manufacturing, logistics, payment processing, marketplace commissions, taxes and return write-offs for a given order.
Any marketing campaign running below this threshold loses money on every incremental transaction, regardless of top-line revenue growth. Knowing your exact break-even point protects your business from scaling unprofitable ad sets.
Many e-commerce merchants assume that a 50% markup between wholesale cost and selling price means they can safely operate at a 2x ROAS. In reality, delivery charges, card processing fees, marketplace commissions, packaging and returned goods all come out of that margin.
After these costs, a theoretical 50% margin can shrink to a contribution margin of, say, 25%. Operating at 2x ROAS under those conditions results in steady cash burn.
Maximum CPA (Cost Per Acquisition) is the highest amount you can afford to pay for an order before ads begin destroying gross profit. It equals your unit contribution margin before advertising.
If your ad platforms report a CPA higher than this figure, campaigns are consuming cash from your existing reserves rather than creating profit.
Merely breaking even does not fund reinvestment or company growth. To establish a profitable target, first subtract your target net profit margin (e.g. 10–15%) from your per-order contribution.
The remaining balance is your Target CPA. Dividing your order revenue by this Target CPA gives the target ROAS you should provide to automated bidding algorithms.
This model evaluates individual order unit economics. Fixed operating expenses such as office leases, full-time salaries, software subscriptions and legal retainers are not deducted at the per-unit level.
Unit contribution margin must accumulate across overall sales volume to cover these company-wide fixed costs and yield bottom-line enterprise profit.
Break-even ROAS = Reported Order Revenue ÷ Maximum CPA (Contribution Margin). Contribution is calculated by subtracting COGS, shipping, payment fees, returns and variable costs from net revenue.
Taxes collected from customers are pass-through liabilities owed to the state. Treating gross tax receipts as business revenue artificially inflates perceived margins and leads to unprofitable ad bids.
It depends on how your store integration (Shopify, WooCommerce, etc.) configures the purchase event. Most standard setups pass the final checkout total (inclusive of VAT). Choose "Incl. VAT" in the calculator if that matches your tracking.
For marketplaces (Amazon, eBay, etc.), check your category fee schedules. For your direct website, check your merchant agreements with payment gateways like Stripe, PayPal, or local merchant acquirers.
Google Ads requires Target ROAS as a percentage. For example, if your break-even ROAS is 4.35x and you aim for target profitability at 6.82x, enter at least 682% into Google Ads campaign settings.
Divide your ad revenue by ad spend. Add your profit margin to see your break-even threshold and net profit immediately.
Calculate gross profit margin and markup from cost and price, or determine required VAT-inclusive selling price from target margin.
Work backwards from monthly revenue targets, average order value and conversion rates to determine required ad spend.
ROAS and CPA are only as accurate as your tracking. Missing or duplicated conversions break every calculation above. Let an independent audit check your measurement.