Break-even CPA calculator

Average order value is what a typical order is worth, net of discounts actually given and returns actually made. Use the figure for the orders this campaign produces rather than the business-wide average; a prospecting campaign selling an entry product and a retargeting campaign selling the flagship have different ceilings.

Gross margin is the share of that order value left after the direct cost of the goods: product, inbound freight, the variable part of payment processing. It is required here, because an order value without a margin describes revenue and revenue cannot pay for media.

Fulfilment cost per order is the per-order cost that does not scale with the order's value: picking and packing, a shipping subsidy, a flat delivery surcharge, the fixed component of a transaction fee. It is optional and worth entering, because it is the cost most often lost inside a percentage.

Profit wanted per order is optional and is what turns a floor into a target. It is the contribution the business intends to keep after paying for the media.

Gross profit per order is the amount the order leaves before anything is spent on acquiring it. At 180 of order value and a 55 per cent margin, that is 99.

Break-even cost per acquisition takes fulfilment out: 99 less 12 is 87. That is the point at which the campaign is level — the media is paid for, the goods are paid for, the order is shipped, and nothing at all is left over.

Target cost per acquisition takes the required profit out as well: 87 less 20 is 67. That is the number a bid strategy should be aimed at, and it is 23 per cent below the break-even figure. The distance between the two is the part people skip, and skipping it is how an account ends up running at break-even while everybody believes it is profitable.

There is no cost per acquisition that travels between businesses, because the ceiling is set entirely by the unit economics behind it. A business selling a 40 order at a 25 per cent margin can afford 10 a conversion; a business selling a 4,000 order at a 60 per cent margin can afford more than two thousand. Both are looking at the same auction and they are not in the same market at all.

That is also why a cost per acquisition that rose is not automatically bad news. If order value rose with it, the ceiling rose too, and the campaign may be further inside its boundary than it was before. Reading the cost without the ceiling beside it is how a mix improvement gets reported as a regression.

The ceiling moves for reasons that have nothing to do with media: a supplier price increase, a shipping rate change, a promotion, a product mix shift. Recompute it when any of those happen, and keep the campaign targets pinned to it rather than to their own history.

Everything below the gross profit line. Rent, salaries, software, the agency retainer, tax: none of it is in this arithmetic, which is why break-even here means the media has paid for itself and not that the business has made money.

It also ignores the future. This is a first-order ceiling. A business with real repeat purchase can afford more than 87 for a first conversion, because the customer will come back — but that argument needs a retention curve and enough cash to survive the gap between paying for the media now and collecting the profit later. The honest sequence is to set the ceiling from the first order, know what the lifetime figure would permit, and move between them as a decision rather than as an assumption.

The instinct is to lower bids, which lowers the cost per acquisition and the volume with it. Work through the alternatives first, because three of the four inputs on this page are not media levers at all.

Raise the order value. A threshold, a bundle or a better-chosen product in the ad raises the ceiling directly, and the ceiling rises by the margin's share of every extra unit of revenue.

Improve the margin. Pricing, packaging and supplier terms move it, and each point of margin raises the ceiling for every campaign at once.

Attack the fulfilment line. A flat per-order cost is often the largest single deduction on a small order and the easiest one nobody has looked at in a year.

Then the media. Improving the rate at which clicks convert lowers the cost per acquisition without touching the auction, and excluding what has never converted lowers it without lowering reach. Bids come last, because they are the only lever on the list that pays for a better cost with less volume.