Break-even ROAS: formula & calculator

The break even ROAS formula is 1 ÷ contribution margin before ads, with margin written as a decimal. Worked example: an order keeps 40% of its net revenue after variable costs and before advertising. Its break-even ROAS is 1 ÷ 0.40 = 2.50×.

This is the point where advertising uses all the contribution from the order. It leaves nothing for fixed overhead or profit. Enter revenue and costs above to find that floor, then set a higher operating target if the business needs money left after ads.

How to calculate break even ROAS

Start with the amount the business earns from an order after discounts and refunds. Use a consistent tax-exclusive basis. Subtract every variable cost that belongs to earning and delivering that revenue, except the advertising cost you are solving for.

The calculation has two stages:

1. Contribution before ads = net revenue minus variable costs before ads.
2. Break-even ROAS = net revenue divided by contribution before ads.

Dividing contribution by revenue gives the contribution margin. The second stage is therefore the same as one divided by that margin. Shopify's contribution margin guide describes contribution as the sales remaining after variable expenses. Our calculator stops before advertising so the remaining amount can be used to solve for ad spend.

Use contribution rather than the product markup shown on a supplier sheet. Delivery and payment costs use the same rupees that would otherwise pay for acquisition. Leaving them out makes the advertising ceiling too generous.

The tool takes two inputs because a cost worksheet should be assembled before touching a campaign budget. Keep the detail in your sheet, then enter the total. You can inspect and correct the cost mix without rebuilding the calculator each time.

Worked example: a ₹1,000 order

The example order produces ₹1,000 of net revenue after discounts, excluding GST. Its pre-ad variable costs are:

Contribution before ads is ₹1,000 minus ₹600 = ₹400. The margin is ₹400 ÷ ₹1,000 = 40%. Advertising can consume ₹400 before the order's contribution reaches zero. Revenue divided by that spend is ₹1,000 ÷ ₹400 = 2.50×.

At 2.50×, the order covers variable costs and advertising. Set a higher target to fund fixed overhead, such as office rent, software and salaries. Reserve that amount before calculating an acquisition budget.

The same example at different ad costs makes the boundary visible:

Keep the full calculation in the sheet. Display rounding to 3.33× does not change the underlying ₹300 acquisition allowance.

Which costs belong in the margin

Include product cost on the same basis as the revenue. Add the packaging used for each shipment, actual freight charges, payment or COD collection fees and other per-order service charges. Use your own invoices rather than a generic rate copied from another store.

Treat returns with a matched revenue and cost policy. Remove refunded revenue from sales. Keep the unrecovered delivery, handling and damage costs that remain after the refund. Do not also subtract the full refund as a cost after removing it from revenue. That counts the same loss twice.

RTO needs particular care. A failed delivery may produce no retained revenue but still create a freight bill. For an order-level model, allocate the period's failed-delivery costs across the successful orders earning that period's net revenue. Reconcile that allocation against the actual expense total.

A returned product that is recovered in saleable condition should not automatically create a permanent loss equal to its entire product cost. Record the actual loss and handling costs. An allowance copied from an old spreadsheet can quietly inflate or understate the acquisition limit.

For a full explanation of choosing costs, use the profit margin calculator. Keep the pre-ad contribution calculation separate from a final net profit calculation.

How to turn break-even ROAS into a target

A break-even floor protects variable contribution. A trading target should also leave room for the business. Decide the amount that must remain per order after advertising, then subtract it from pre-ad contribution.

In the worked order, reserve ₹100 after ads. That is 10% of the ₹1,000 revenue. The advertising allowance becomes ₹400 minus ₹100 = ₹300. The required revenue ROAS is ₹1,000 ÷ ₹300 = 3.33×.

Written as rates, target ROAS = 1 ÷ (pre-ad contribution margin minus desired post-ad contribution rate). Use 0.40 and 0.10, giving 1 ÷ 0.30. Do not put 40 and 10 into that expression.

The desired remainder has to cover the fixed costs and profit you intend to fund. Set the reserve from your own overhead and profit requirement. If the required remainder equals or exceeds pre-ad contribution, there is no positive advertising budget left.

Apply this target to the same revenue definition you used to build the margin. A target calculated on tax-exclusive retained revenue does not compare directly with a report that includes tax, shipping charges or subsequently cancelled purchases.

Why platform ROAS can differ from this result

Google Ads defines conversion value per cost as conversion value divided by advertising cost. Its value depends on the conversion values sent to the platform. The ratio does not automatically know your landed cost or the status of a refunded order.

Before comparing the platform result with the floor, check which purchase events are included. Match the attribution window and the way revenue is valued. An account can report a healthy purchase ratio while the store retains much less revenue than the events originally recorded.

Use the ROAS calculator to inspect the ratio itself. For budget decisions across the whole business, also calculate net store revenue divided by total ad spend. Keep that blended ratio labelled separately from a single platform's attributed return.

After a budget change, compare the additional retained revenue and costs with the additional spend. The economics of the extra orders matter more than the account's historical average.

Zero margin and other edge cases

If variable costs equal revenue, the denominator is zero. No finite advertising return creates positive contribution within this model. If costs exceed revenue, the product is already losing money before ads. Fix the order economics before buying more of those orders.

For a mixed basket, aggregate revenue and costs first. Dividing total contribution by total revenue gives a revenue-weighted margin. An unweighted average of SKU margins gives a tiny low-priced item the same influence as the main product.

Recalculate when the offer changes. A discount reduces revenue immediately while product and delivery costs may remain unchanged. Bundles, prepaid incentives and free-shipping thresholds should each have their own cost row. Use the actual realised price rather than the crossed-out list price on the product page.

Before increasing a budget, check that stock, fulfilment and cash collection can support it. Match the acquisition budget to COD settlement dates and inventory payments so the business can fund the orders it wins.