Break-even ROAS, the formula and a calculator to run it

Break-even ROAS is one division: 1 divided by your contribution margin. The part almost every published guide gets wrong is the denominator. Gross margin leaves out shipping, pick-pack, payment fees and returns, all of which scale with orders, and putting them back typically moves the break-even point by more than a full turn. This is the version that survives contact with a bank statement.

How do you calculate break-even ROAS?

One division. Break-even ROAS is 1 divided by your contribution margin, expressed as a decimal.

At 40% you need 2.5x before an ad has contributed anything. At 25% you need 4x. That number is a floor rather than a target, and it doubles as the ceiling on what a first order can cost to acquire.

All the difficulty is in the denominator. Contribution margin is what is left of an order after every cost that varies with the number of orders, excluding advertising.

This piece is for operators who buy media against their own P&L and want the two numbers to reconcile. By the end you'll have a break-even ROAS you can defend, a maximum first-order CAC and a clear view of where the widely quoted version of this calculation goes wrong.

Why is gross margin the wrong denominator?

Because gross margin stops at cost of goods. Shipping, pick-pack, payment fees and returns are all paid out of the same order, they all scale with order count, and none of them appear in it. Leaving them out doesn't make the answer approximate. It makes it wrong in a known direction, by roughly the cost of shipping a box.

The size of the error isn't constant either, which is why a single rule of thumb can't rescue it. Below are three stores worked the same way. Each assumes payment and platform fees of 3% of order value, a return rate applied against the gross profit on the returned order, and the shipping and pick-pack figures shown in the paragraph that follows. The apparel store uses the 19.3% online return rate that NRF and Happy Returns published in October 2025, not a category-specific figure, for reasons covered further down.

The gap is 1.64 turns on the first store, 1.03 on the second and 0.96 on the third. It widens as order value falls, and the mechanism is worth naming because it decides which businesses this arithmetic hurts most: shipping and pick-pack are fixed per order, so $6.50 eats 23% of a $28 order and 2.7% of a $240 one. Low-AOV brands pay the largest hidden tax and are the ones most likely to be using the shortcut.

The relationship between margin and required ROAS is also not a straight line, and that shape matters more than any single number on it.

Ten points of margin between 60% and 50% costs you 0.33 turns of ROAS. The same ten points between 30% and 20% costs 1.67 turns. So a $2 packaging change or a shipping renegotiation is worth far more to a thin-margin store than the same change is to a fat-margin one, and the temptation runs the other way because thin-margin stores tend to chase the media instead.

What belongs in contribution margin, and what does not?

The test is simple. If the cost goes up when you ship one more order, it belongs in contribution margin. If it doesn't move whether you ship 400 orders or 500, it sits below the line and gets paid out of contribution rather than deducted from it.

Marketplace selling adds a line that catches people out, because the headline commission is rarely the whole of it. If any of your volume goes through TikTok Shop, its referral fee, the affiliate commission and the ad spend attributed to the shop all belong in this list — we costed what selling on TikTok Shop actually takes, line by line.

Fill in your own numbers below. The model matches the tables above, including the way returns are charged against the margin on the returned order rather than against the full order value.

What does the arithmetic look like on a real order?

Common Thread Collective published a worked first-order model in January 2024 that is the clearest public version of this, so it's worth walking through rather than paraphrasing. It starts from $59 of first-order revenue and $21 of cost of delivery.

Two things are worth pulling out. The first is that 2.27 is simply 59 divided by 26, which is a useful check that the model hangs together rather than a separate assumption. The second is the distance between 1.55x and 2.27x: the pure break-even and the operating target aren't the same number, and the 0.72 turns between them is everything the cost-of-delivery line doesn't cover — rent, salaries, software, agency fees and whatever profit the business is meant to make.

Maximum CAC comes from the same place, and it is the number to write on the wall before any budget goes live.

Is 3:1 LTV to CAC a target worth having?

Not as a benchmark, no. The ratio came from software. David Skok set it out in SaaS Metrics 2.0 for subscription businesses, and the two assumptions sitting underneath it are software-scale gross margins and contractual recurring revenue that renews unless somebody cancels. Neither describes a store. The three worked above run gross margins of 50-65% and contribution margins of 30-39%, on revenue that has to be won again with every order.

The clearer tell is that the ratio carries no time bound. Three to one over what period? A DTC lifetime value quoted across 24 months and a SaaS one quoted across a contract term are different kinds of object, and dividing either by CAC produces something that has the shape of a benchmark without the substance of one.

You'll also find LTV to CAC tables by vertical, quoted to one decimal place. Follow the citations and they lead to other articles citing other articles, with no sample size, no date range and no method disclosed anywhere in the chain. We don't publish those and you shouldn't quote them. Twelve ecommerce benchmarks with no source behind them traces several of these chains to where they break.

Should you ever spend past break-even on the first order?

Yes, deliberately. First-order break-even is a choice about how growth gets financed, not a law. A brand with genuine repeat purchase can rationally lose money on order one and recover it on orders two through five, and plenty of good businesses were built exactly that way.

Three things separate that from an accident.

You have measured the repeat curve on your own cohorts. Not on a category benchmark: we have found no vendor publishing category-level 90, 180 and 365-day cumulative-revenue cohort curves, and the companies best placed to produce them sell the tooling instead. Order sequence is one of the few things every store already owns, so count it yourself.

You know the payback period in weeks and you have the cash to bridge it. Contribution arriving in month seven doesn't pay a supplier in month two, and a payback model that ignores working capital is a way of running out of money while the spreadsheet says everything is fine.

And you have written down how much you are prepared to lose per order and for how long. An unbounded commitment to investing in acquisition is how a nine-month runway turns out to have been a four-month one.

What does break-even ROAS not tell you?

Quite a lot, and the honest limitations are the reason to treat it as a floor rather than a verdict.

It assumes attributed sales were caused. Across 640 Meta incrementality experiments published by Haus in July 2025, Meta under-reported its own incremental contribution by about 15% on average for DTC-only brands measuring on click-only attribution, which is not Meta's default setting — while automated campaigns in the same dataset over-reported themselves by 12 percentage points relative to manual. The reported ROAS you compare against your break-even can be wrong in either direction, and knowing which requires a test rather than a dashboard.

It's a first-order number, so it says nothing about repeat. It is blind to mix, and a blended account average will happily hide a SKU that loses money on every unit. And it assumes the cost lines hold still, which they don't: UPS and FedEx both announced average general rate increases of 5.9% for 2026. We were not able to reach either carrier's rate page to confirm the figure or its effective date, so check your own contracted rates rather than this one. The realised increase once dimensional weight and additional-handling surcharges stack is commonly reported at 8-12%, though we have found no primary source for that band and treat it as unverified.

One more caveat on that first figure. Category return rates for apparel are widely quoted at 24-35%, and we have not found a primary source for them, so the tables above use the 19.3% online average instead, remembering it is NRF's estimate rather than a measurement. If your own returns run higher, use your own number — it is one of the few inputs here that every store can measure exactly and almost nobody does.

Work it out once, properly. Then stop arguing about it. Most accounts that fail on economics failed before the first impression served, because the break-even was computed on gross margin and looked comfortably clear.