Break-Even ROAS Calculator

What break-even ROAS is

Break-even ROAS is the return on ad spend at which a sale is worth exactly zero to you — one dollar of profit above your costs, and one dollar below. It is the reciprocal of your contribution margin:

Break-even ROAS = 1 ÷ contribution margin

Contribution margin is what is left of the selling price after every cost that is not advertising: landed cost including duty, platform commission, payment processing, fulfilment shipping, and the cost of returns. Expanded, that is:

BE ROAS = price ÷ (price − landed − platform fee − payment fee − shipping − returns)

Everything on this page runs off that one line. There is no proprietary model and nothing withheld for the paid tier — the formula is a commodity, and publishing it is how you check our arithmetic against your own.

How each input moves the floor

Selling price

The product price only. If you charge for shipping, that revenue belongs against your fulfilment cost, not here — netting it into price flatters the margin and lowers your floor below where it really is.

FOB unit price

The base of the customs value. Duty is assessed on the goods, not on the goods plus international freight, which is why this calculator applies the rate to FOB rather than to landed cost.

Packing before import vs packaging after

These are not the same line. Packing you pay for separately from the goods is part of the dutiable value, so duty applies to it; gift boxes and mailers added once the goods are in your warehouse are not, because they did not exist at the border. Lumping them together understates duty on every unit.

Tariff (origin, category, Section 301 list)

Duty enters COGS, so it compresses contribution margin directly. The rate is built from stacked layers — see How that duty rate is built in the result panel, where every layer links to its source.

Payment fee, percentage and fixed

The fixed component is the one people forget. At a $25 order the standard $0.30 is 1.2% of revenue; at $200 it is 0.15%. On low-ticket SKUs it is a meaningful slice of the floor.

Return rate and loss per return

A return costs more than the sale returned. You refund the price, you have already paid the processor, and duty is not refunded when goods go back. Loss per return of 1 means full refund with nothing recovered; lower it only if returned units genuinely go back into sellable stock.

A worked example, with and without duty

Take the SKU loaded into the calculator above: a knit apparel item selling at $49, bought at $9 FOB from China, $2.40 inbound freight per unit, $0.40 of packing paid separately from the goods, $0.60 clearance, $5.50 to ship to the customer, 2.9% + $0.30 payments, 6% returns at full loss.

Before duty, landed cost is $12.40, contribution margin is 53.96%, and the floor sits at 1.85x. Now add the 2026 stack for knit apparel out of China — 16.5% MFN, 7.5% Section 301 List 4A, 12.5% Section 301 forced labor, 36.5% combined. Customs values the goods at $9.40, not $9, because packing you pay for separately is part of the dutiable value. Duty comes to $3.43 per unit, landed cost becomes $15.83, contribution margin falls to 46.96%, and the floor moves to 2.13x.

That is a 0.28x move from a line item that never appears in Ads Manager, and it costs you $3.43 of the $26.44 you previously had to spend acquiring each order — 13% of your entire advertising budget for that SKU, gone before you write a single ad. Toggle the tariff switch above to reproduce it.

How your floor compares to channel benchmarks

Published ROAS benchmarks are worth less than they look. The 2026 reports below do not even measure the same thing — some quote a median, some a mean, some a loose “typical range” — and for the same channel their figures differ by more than 2×:

Questions

What is a good break-even ROAS?

There is no good break-even ROAS in the abstract — it is an output of your cost structure, not a target you choose. A 70% margin SKU breaks even near 1.4x; a 25% margin SKU needs 4.0x. The number that matters is whether your floor sits below what your channel realistically returns. If your floor is 4.0x and you buy on TikTok, the arithmetic is telling you to fix the product economics, not the campaign.

Does ROAS include COGS?

No, and that is the whole problem. Platform-reported ROAS is revenue divided by ad spend — it knows nothing about your cost of goods, duty, payment fees, fulfilment, or returns. A 3x ROAS in Ads Manager can be a loss. Break-even ROAS is the bridge: it converts your real per-unit costs into the ROAS threshold that Ads Manager number has to clear.

How do tariffs change my break-even ROAS?

Duty lands in COGS, so it compresses contribution margin, and break-even ROAS is one divided by contribution margin. The effect is non-linear: on a thin-margin SKU a few points of duty move the floor far more than the same points would on a fat-margin one. Use the tariff toggle above to see the before-and-after on your own numbers.

Should I use break-even ROAS or break-even CPA?

They are the same fact in two units. Break-even ROAS is a ratio you set as a bid target; break-even CPA is a dollar amount you compare against actual cost per purchase. Use ROAS when your AOV moves around, CPA when it is stable. Both come out of the same contribution margin.

Why does the calculator ask for a loss-per-return factor?

Because a return is not a cancelled sale. You refund the price, you have already paid the payment processor's fee, and — since the de minimis exemption ended — you do not get the duty back either. Set the factor to 1 if you refund in full and recover nothing. Lower it if the goods come back sellable and you can put them into stock.

Is my data stored anywhere?

No. Every calculator on this site runs entirely in your browser. Nothing you type is sent to a server, and there is no account to create. The share link encodes your inputs in the URL, so it only leaves your machine if you copy it and send it yourself.

Sources and last update

Duty rates last verified 2026-08-22. Benchmark ranges last reviewed 2026-08-22.

• USITC Harmonized Tariff Schedule — MFN general duty rates
• USTR — Section 301 forced labor actions, effective 24 July 2026
• USTR — China Section 301 tariff actions and exclusions
• TrueProfit — What's a Good ROAS in 2026
• EcomCalcTools — Ecommerce ROAS Benchmarks 2026 by Channel
• Hawky — What Is a Good ROAS for Ecommerce, 2026 Benchmarks

Duty figures are category-level approximations. MFN and Section 301 rates apply per 10-digit HTS code and vary widely inside a category. These are planning estimates — your customs broker’s classification governs what you actually pay. Full workings on the methodology page.