Start With the Question Behind the Question
How much should a small business spend on Google Ads is the wrong place to start. The real question is what a customer is worth to you, because that single number sets everything else. If a new client is worth £500 over their lifetime, you can comfortably spend far more to win one than a business whose average sale is £30. Your Google Ads budget should be a consequence of your maths, not a figure plucked from a forum.
Google will happily accept any budget you give it, which is exactly why discipline matters. The platform is built to spend whatever you allow. Your job is to make sure every pound spent is tied to a number you understand, so growth is a decision rather than a hope.
The Three Numbers You Need Before You Spend a Penny
Three figures turn advertising from a gamble into a calculation. Know these and you can judge any campaign honestly within a few weeks. Without them you are simply guessing whether the ads are working.
Spend an evening estimating these even if you have to use rough averages. Conservative estimates are fine to start; you will sharpen them as real data comes in.
- check_circleAverage order or client value: what a typical customer is worth, ideally over their lifetime, not just the first sale.
- check_circleConversion rate: the share of enquiries or clicks that turn into paying customers, on the ad and on your website.
- check_circleMaximum cost per acquisition: the most you can pay to win a customer and still make an acceptable profit.
Setting a Sensible First Budget
For most small UK businesses, a realistic starting point sits somewhere between £500 and £1,500 per month, with many testing at around £750 to £1,000. The aim of this first budget is not profit, it is learning. You are buying data about which keywords, ads and landing pages actually convert, and that data is what makes later spend efficient.
Beware of going too small. A £150 monthly budget on competitive keywords often buys too few clicks to learn anything, leaving you with noise rather than signal. It is usually better to run a focused campaign on a tight set of keywords with enough budget to gather real results than to spread a tiny amount across everything.
Why Cost Per Click Varies So Much
The same budget buys wildly different volumes depending on your sector. A click in a low-competition local trade might cost 60p to £2, while fiercely contested areas such as legal services, insurance or B2B software can run to £10, £20 or more per click. This is set by an auction, so the more advertisers chasing a keyword, the higher the price.
This is why two businesses spending £1,000 can have completely different experiences. Before launching, use Google's Keyword Planner to see estimated costs for your specific terms. That five-minute check tells you whether £1,000 buys you 1,500 clicks or 80, and shapes whether your budget is even viable for the keywords you want.
From Budget to Leads: A Worked Example
Imagine you spend £1,000 in a month and your average cost per click is £2. That buys roughly 500 clicks. If your landing page converts 5 per cent of those into enquiries, you get 25 leads, so each lead costs £40. If you close one in four of those leads, you win around 6 customers at a cost of roughly £167 each.
Now the budget question answers itself. If a customer is worth £600 to you, spending £167 to win one is excellent and you should scale up. If a customer is worth £120, you are losing money and need to fix conversion or pause. The arithmetic, not your gut, tells you what to do next.
Scale Only When the Numbers Prove It
The golden rule is to increase spend only once a campaign reliably returns more than it costs. When your cost per acquisition sits comfortably below what a customer is worth, and stays there for several weeks, you can raise the budget in steps of perhaps 20 to 30 per cent rather than doubling overnight. Big jumps disrupt the system Google uses to optimise and make results harder to read.
Resist scaling on a single good week. Advertising is noisy, and one lucky run can flatter a campaign. Look for a consistent pattern across a month or more before committing more money, and keep watching the cost per acquisition as you grow, because it often creeps up as you reach beyond your best keywords.
Where Small Budgets Get Wasted
Most wasted ad spend is avoidable. The biggest culprit is sending traffic to a slow or generic page instead of one built to convert that specific search. The second is broad match keywords with no negative keywords, which lets Google show your ad for loosely related terms that never buy. The third is ignoring the account for weeks, so losing keywords quietly drain the budget.
Tracking is the quiet killer. If you cannot see which clicks became enquiries or sales, you are flying blind and cannot judge any of this. Set up conversion tracking before you spend, not after, so every pound is accountable from day one.
- check_circleNo conversion tracking, so you cannot tell what is working.
- check_circleSending clicks to a weak homepage instead of a focused landing page.
- check_circleBroad keywords with no negative keyword list filtering out junk searches.
- check_circleSetting and forgetting, rather than reviewing performance weekly.
Should You Run Ads Yourself or Hire Help?
If your monthly budget is modest, under roughly £750, doing it yourself with care often makes sense, since an agency or freelancer fee could swallow most of the spend. Above that, professional management can pay for itself by cutting waste and improving conversion, even after their fee. Management typically costs a flat monthly fee or a percentage of ad spend, often around 10 to 20 per cent.
Whoever runs it, insist on clarity. You should always know your cost per lead, your cost per customer and how those compare to a customer's value. A good partner ties ad performance to your website too, because the cleverest campaign still fails if it lands people on a page that does not convert.
Frequently asked questions
How much should a small business spend on Google Ads per month?expand_more
Most small UK businesses sensibly start between £500 and £1,500 a month, often around £750 to £1,000. The goal of that first budget is to learn which keywords and pages convert, not to turn an immediate profit. Once a campaign reliably wins customers below what they are worth to you, scale the budget up in steps.
Is a £200 per month Google Ads budget worth it?expand_more
It can work for a low-competition local service where clicks cost under £2, but on competitive keywords £200 often buys too few clicks to gather meaningful data. If your sector has high click costs, you are usually better focusing a slightly larger budget on a few tight, high-intent keywords than spreading a small amount thinly.
How do I know if my Google Ads are profitable?expand_more
Compare your cost per acquisition, what you pay to win one customer, against what a customer is worth to you. If you spend £167 to gain a customer worth £600, you are profitable and should scale. If they are only worth £120, you are losing money. This requires conversion tracking set up before you start spending.
Should I hire someone to manage my Google Ads?expand_more
If your budget is under about £750 a month, careful self-management often makes sense, as fees could eat most of the spend. Above that, professional management often pays for itself by cutting waste. Management usually costs a flat fee or roughly 10 to 20 per cent of ad spend. Either way, insist on clear reporting on cost per lead and per customer.
Why is my cost per click so high?expand_more
Cost per click is set by an auction, so the more advertisers bidding on a keyword, the higher the price. Competitive sectors like legal, insurance and B2B software can exceed £10 per click, while niche local trades may be under £2. A low Quality Score from weak ads or landing pages also pushes your costs up, so improving relevance can lower them.