Free tool
Ad spend calculator
Enter your average order value, margin, conversion rate and cost per click. We tell you how much you can pay per customer, how much to spend per month and where the ceiling is beyond which you lose money.
Your numbers
The result
Fill in order value, margin, conversion and cost per click to see the result.
- Cost per customer ceilingThe most you can pay for a customer without losing money.
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- Cost per customer todayCost per click ÷ conversion rate.
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- Maximum cost per click
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- Break-even ROAS
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- Expected ROAS (first purchase)
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- Left per customer after ads
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- Monthly spend
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- Monthly spend ceilingBeyond this spend, each new customer costs more than they bring.
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- Monthly spend at your target
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- Clicks needed per month
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- Monthly profit after ads
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As you scale, each customer usually gets more expensive: that is why the calculator tells you the ceiling instead of promising an optimal figure. It is arithmetic: the same numbers always give the same result.
How it is calculated
- Profit per customer = order value × margin × purchases per customer. That is the ceiling: paying more for a customer loses money.
- Cost per customer today = cost per click ÷ conversion rate.
- Break-even ROAS = 1 ÷ margin. Below it, the campaign does not pay for itself on the first purchase.
- Monthly spend = customers × cost per customer; spend ceiling = customers × cost per customer ceiling.
Frequently asked questions
How much should I spend on ads per month?
What it costs to win the customers you can serve: customers per month × cost per customer. The limit is the ceiling: customers × (order value × margin × purchases). Above that figure each new sale costs more than it brings.
What is the maximum CAC I can afford?
The gross profit a customer brings: their average order value times your margin times how often they buy. If a customer spends 50 at a 40% margin and buys twice, you can pay up to 40 to win them without losing money.
What ROAS do I need to break even?
One divided by your margin. At a 40% margin you need a 2.5 ROAS on the first purchase; at 25%, a 4.
Want it to fill itself in?
Inside SalesMarketing the calculator reads your sales and your ads and fills itself in with your real numbers.
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