How much does Google Ads cost? A budget method, not a guess

"What should our Google Ads budget be?" Most businesses answer it by feel: a round number that sounds safe. There is a better way: work it out backwards from your own business numbers. Here is the method we use.

How much does Google Ads cost?

There is no price list. You pay per click, and the price of a click is set in an auction for each search. You decide the maximum: your own daily budget. So the useful question is not "what does Google Ads cost?" but "what can I afford to pay for one customer?"

This article deliberately contains no "average cost per click" figures. Costs vary by country, industry, keyword and season. Your own numbers, from your account and Google's Keyword Planner, are the ones that matter.

Step 1: Work out what a new customer is worth

Start with the business, not with Google.

• What is the average value of one sale or booking?
• What is your margin on it?
• Do customers come back? If so, what is a customer worth over a year?

From this, decide the maximum you can pay to win one customer and still be happy. In Google Ads terms, that is your target cost per acquisition (CPA).

The question changes from "is this expensive?" to "is this below what a customer is worth?"

Step 2: Decide what counts as a conversion

A conversion is the action that matters: a booking, a call, a form, a request for a quote. Set up tracking for it before the first ad runs.

If the sale happens offline, track the closest step, such as a call or a form, and note how many turn into customers.

Step 3: Estimate the cost of one conversion

Two numbers decide it:

• Cost per click for your keywords. Get estimates from Google's Keyword Planner for your own keywords and location.
• Conversion rate: the share of visitors who take the action. Use your website's current rate as a starting point.

Cost per conversion = cost per click ÷ conversion rate.

If that estimate is far above your target CPA, you have learned something before spending anything: improve the landing page, choose more specific keywords, or rethink the offer.

Hands with a calculator and notebook

Step 4: Set a budget for a real test

Now the budget follows:

Monthly test budget = target CPA × the number of conversions you want to learn from.

Then divide by 30.4 to get your daily budget. That figure comes from Google itself: on a given day a campaign may spend up to twice its average daily budget to catch busy periods, but over a month it will not spend more than 30.4 times the average daily budget.

Two practical points:

• Give it time. Campaigns need a few weeks to learn. A common guideline is to wait at least two weeks, or two full conversion cycles, before judging a change.
• Do not split a small budget too thin. One focused campaign with enough budget learns faster than five starved ones.

Is a small monthly budget enough?

Run the numbers from steps 1 to 4. If your monthly budget cannot buy enough clicks for even a handful of conversions at your cost per click, it is too small to learn from, whatever the amount. In that case, narrow the campaign to your most specific keywords and one location, or fix the landing page first. If it can, start there and let the results decide the next step.

Step 5: Protect the budget with 2026's new controls

Google is adding controls that matter especially for smaller budgets.

Channel prioritization. Announced on 14 October 2026 and rolling out over the coming months for Search, Shopping, Performance Max and Demand Gen. You can mark channels such as Search partners or the Display Network as low priority and cap them at a percentage of your daily budget. Google describes this as best effort, not a guarantee.

One date to note: from February 2027, Search campaigns with the Display Network switched on lose their current spend allocation setup. Google's advice for keeping today's behavior is to set the Display Network to low priority with a 50% budget allocation.

AI Max. Google's AI now chooses more of the searches your ads appear on, so your exclusions and landing page content steer where the budget goes.

Step 6: Scale by rule, not by mood

Decide in advance when you will change the budget:

• Raise it when your cost per conversion is below target and you are losing impressions because the budget runs out.
• Hold it while the campaign is still learning or results are close to target.
• Lower it or fix the basics when the cost per conversion stays well above target after a fair test.

Write these rules down.

Is Google Ads cheaper than Facebook?

They sell different things. Google Ads reaches people who are already searching; Facebook and Instagram ads reach people who are not searching yet. A click on either can be cheaper or dearer depending on your market. Compare them on cost per customer, measured in your own accounts, not on cost per click.

Your budget worksheet (a Google Ads budget calculator on paper)

• Value of one customer: ______
• Maximum cost per customer (target CPA): ______
• Conversion you track: ______
• Estimated cost per click (Keyword Planner): ______
• Current conversion rate: ______
• Estimated cost per conversion (4 ÷ 5): ______
• Conversions to learn from: ______
• Monthly test budget (2 × 7): ______
• Daily budget (8 ÷ 30.4): ______
• Review date: ______

What to take away

• Start from what a customer is worth, not from a round number.
• Track conversions before you spend.
• Budget = target CPA × conversions you need to learn.
• Give tests time, and set rules for scaling in advance.
• Use the new channel controls to keep small budgets on Google Search.

Not sure whether ads fit your business at all? See how we run Google Ads next to SEO. Want us to fill in the worksheet with you? Book a call.