Spend what your own numbers allow, and work it out before you look at anyone's range. Three sums give you a budget: what a new customer is worth, the most you can pay for a lead, and how many customers you want. The ranges that guides quote are useful only as a check afterwards.
How do you work out a budget from what a customer is worth?#
Step 1. What is a new customer worth? Not the price they pay. Take what is left after your costs for the job or the order, and decide how much of that you are willing to give up to win the customer. A plumber who keeps £300 from a typical job might be willing to spend £100 of it to get the job.
Step 2. What may a lead cost? A lead is an enquiry: a form, a message, a call. Not every enquiry becomes a customer. Count how many out of ten do, honestly. The most a lead may cost is the customer's worth multiplied by that share.
Step 3. What is the daily budget? Decide how many new customers you want a month. Work back to the number of leads you need, multiply by the most a lead may cost, and divide the month into days.
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.
The calculator does this arithmetic, and it is simple enough to do on paper:
- The most a lead may cost = what a new customer is worth × (leads that become customers out of 10 ÷ 10).
- Leads needed a month = customers you want a month × 10 ÷ leads that become customers out of 10.
- Monthly budget = leads needed a month × the most a lead may cost.
- Daily budget = monthly budget ÷ 30.
A worked example. A new customer is worth £100 to you (or $100; the sums are the same in any currency). Two enquiries out of ten become customers. You want five new customers a month.
- The most a lead may cost: £100 × 2 ÷ 10 = £20.
- Leads needed: 5 × 10 ÷ 2 = 25 a month.
- Monthly budget: 25 × £20 = £500.
- Daily budget: £500 ÷ 30 = about £17 a day.
This is the most you should spend to get those customers, not a forecast that the ads will deliver them. If leads cost you less than £20, you need less budget. If they cost more than £20, the ads lose money at that customer worth, and the thing to change is the page, the offer or the price, not the budget.
What do guides say a small business should spend?#
These ranges were published in 2026. They disagree, which is the reason to do your own sums first.
| Source and date | What it suggests |
|---|---|
| Whito, UK, updated September 2026 | £300 a month (£10 a day) as the minimum for meaningful data; £500 a month as right for most small businesses; £100 a month tests one audience with one ad and nothing more |
| Lilach Bullock, UK, 2026 | £500–£1,500 a month; at least £15–£20 a day; £210–£280 over two weeks as the smallest real test |
| 99 Dollar Social, US, updated February 2026 | $10–$20 a day, about $300–$600 a month, to begin testing |
| Adwave, US, July 2026 | $1,000–$1,500 a month as a common starting point; $20–$50 a day per campaign |
In a survey of more than 250 US marketing professionals that WebFX reports on its 2026 pricing page, 63% said they spend $500 a month or less on Facebook ads.
What does a lead cost on Facebook?#
Published averages vary widely, by country, by trade and by who measured.
| Source and date | Cost per lead |
|---|---|
| Whito, UK, 2026 | £8–£25 as the UK average range |
| Startups.co.uk, UK, updated February 2026 | £10–£40 or more, with an average of £17.60 |
| WebFX, US, 2026 | Typically $8–$25, higher when selling to other businesses |
| WordStream, US, 2025 benchmarks | $27.66 on average across industries, from $3.16 for restaurants and food to $76.71 for dentists |
Use these to check your Step 2 figure. If the most you can pay for a lead is £5 and the published range for the UK starts at £8, the plan is tight before you have spent anything. A benchmark cannot tell you what your own leads will cost; only running the ads does.
Is £10 a day enough?#
It is enough to start and to learn something, and it is slow. Whito's 2026 guide treats £10 a day as the minimum for meaningful data. Two things follow from a small budget.
- Few leads, so slow answers. At £10 a day and £20 a lead you get about 15 leads a month. One good or bad week changes the picture, so judge over a month, not over three days.
- Meta's system learns from results. An ad set needs around 50 of the results it is aiming for before delivery settles, according to Browser Media's explanation of the learning phase (2022). A small budget reaches that number slowly or not at all, so performance can stay uneven.
If your ads brought sales for three days and then seemed to die, a budget too small to give the system steady results is one possible reason.
The ad budget is only what you pay Meta. Photos, video and anyone you pay to manage the ads are extra; see Agency, DIY or an AI agent.
What Madder does about budgets#
Madder drafts a campaign with a daily budget and shows it to you before anything is created; the campaign is then created paused in your own Meta ad account, and switching it on is a second approval. A raise above Madder's limit for one change or one day is refused before anything is sent to Meta. Madder does not predict what a lead will cost, and it shows no lead count or cost per lead until you have chosen which recorded actions count as a lead. See Budgets and the most you pay and How Madder works.
Questions people ask#
What is the minimum budget for Facebook ads?
Guides published in 2026 put a workable minimum at about £10 a day in the UK (Whito) and $10–$20 a day in the US (99 Dollar Social). Less than that can run, but it produces too few results to learn from.
How much should a plumber, a salon or an online shop spend?
Use the same three sums with your own figures: what a new customer is worth, how many enquiries out of ten become customers, and how many customers you want. Published lead costs differ a lot by trade; WordStream's 2025 US benchmarks range from $3.16 for restaurants to $76.71 for dentists.
What is a good cost per lead?
One that leaves you money after the customer pays. Multiply what a customer is worth by the share of leads that become customers; anything under that figure works for you, whatever the average is.
I spent £300 and got nothing. Was the budget too small?
Possibly, but first check whether the ads were shown, whether people clicked, and what they found on the page. A small budget makes results slow; it does not explain clicks that never turn into enquiries.