The most you can pay for a lead is what a new customer is worth to you, multiplied by the share of leads that become customers. A lead is an enquiry: a form, a message or a call. Type your own numbers in below. The answer is a ceiling. Above it, each new customer costs you more than you keep.
Work out your own numbers
The figures are in whatever currency you typed the customer's worth in. It is arithmetic on your own numbers: the most you could pay and still break even, not a forecast of what ads will cost.
How the sum works#
The calculator uses three numbers that only you know.
- What a new customer is worth. Use what you keep, not what they pay. Take the price of a typical job or order and subtract what it costs you to deliver it.
- How many leads out of 10 become customers. Count honestly. Include the people who never reply.
- How many new customers you want a month.
It then does four sums.
- The most a lead may cost = what a customer is worth × leads that become customers ÷ 10.
- Leads you need a month = customers you want × 10 ÷ leads that become customers.
- Monthly ad budget = leads you need × the most a lead may cost.
- Daily ad budget = monthly budget ÷ 30.
A worked example#
A dog groomer charges £60 a visit. After shampoo, rent and time, she keeps £35. A new customer comes back about six times in a year, so one new customer is worth about £210 to her over that year. She decides to count £150 of that, to stay on the safe side.
Three enquiries in ten become customers. She wants eight new customers a month.
- The most a lead may cost: £150 × 3 ÷ 10 = £45.
- Leads needed: 8 × 10 ÷ 3 = about 27 a month.
- Monthly budget: 27 × £45 = about £1,200 at the very most.
- Daily budget: about £40 a day at the very most.
That is the ceiling, the point at which she breaks even over a year. She would be wise to start much lower, perhaps at a third of it, and see what a lead really costs her.
The same sums work in dollars or any other currency.
What margin should you leave?#
Breaking even is not the goal. Decide how much of a customer's worth you are willing to spend to win them.
| If you spend this share of a customer's worth | What it means |
|---|---|
| All of it | You break even. Worth it only if customers come back or refer others |
| Half | You keep half of what the customer is worth |
| A third | A cautious plan with room for leads that cost more than expected |
To use a margin, type the reduced figure into the first box. If a customer is worth £150 and you will spend half, type 75.
Is your answer realistic?#
Compare your ceiling with what leads are reported to cost.
- In the US, WordStream's 2026 report puts the typical cost per lead on Facebook at $27.39 across industries, with a wide spread by trade.
- In the UK, Startups.co.uk's 2026 guide gives £10 to £40 or more, with an average of £17.60.
If your ceiling is well below these, ads are unlikely to pay at today's price and close rate. Change one of the three numbers first: raise the price, sell something customers come back for, or answer enquiries faster so more of them become customers. More figures by trade are in What does a lead cost on Facebook, by industry?.
What the calculator cannot tell you#
It cannot tell you what ads will cost. It is arithmetic on your own numbers and it makes no forecast. Two businesses with the same ceiling can pay very different prices for a lead, because their photos, pages and areas differ.
It also treats every lead as equal. In practice some kinds of enquiry are worth more than others, which is why it helps to decide what you count. See Lead form or your website?.
How Madder uses these numbers#
When you describe what you are promoting, Madder asks for a daily budget and the most you will pay for a lead. It drafts the campaign around them and shows you the plan before anything exists on Meta. Once ads run, Madder shows your real cost per lead, counted only from the actions you confirmed as enquiries. Its daily check-up, if you switch it on, compares each campaign with your own account's cost per lead and may suggest a pause or a budget change. Madder does not predict what a lead will cost you.
See Setting a daily budget and the most you will pay per lead and How much should you spend on Facebook ads?.
Questions people ask#
How do I calculate the most I can pay for a lead?
Multiply what a new customer is worth to you by the share of leads that become customers. If a customer is worth £150 and two in ten enquiries become customers, the most a lead may cost is £30.
What is a break-even cost per lead?
It is the cost per lead at which ads neither make nor lose money. Above it you pay more to win a customer than the customer brings in. Below it you keep the difference.
Should I count repeat business in what a customer is worth?
Yes, if customers really do come back, and only for a period you can count on, such as a year. Be careful with guesses. A lower figure gives a safer ceiling.
My ceiling is lower than the average cost per lead. Should I still advertise?
Probably not yet. Published averages are rough, but a ceiling far below them is a warning. Raise what a customer is worth or the share of enquiries you win, then run the sums again.