Google advertising budget – how much should a business spend?

Start with customer value and the outcome you want

Define what advertising should deliver: new customers, online orders, appointments or qualified requests for a quote. Visitor numbers alone do not tell you whether the investment is profitable. Agree how the outcome will be confirmed through your order system or sales records.

An acceptable customer acquisition cost depends on the margin a customer contributes, fulfilment costs and how quickly the investment needs to pay back. Repeat purchases can be included when there is evidence for them. Using only first-sale revenue or an optimistic lifetime-value estimate can produce an excessive budget.

Calculate the media budget through the whole sales process

For a lead-generation business, divide the target number of new customers by the lead-to-sale rate to find the leads required. Divide that lead count by the website’s lead conversion rate to find the clicks required. Multiply the clicks by the estimated average cost per click to calculate the media budget.

Illustrative example: a business wants ten new customers, one in four leads becomes a customer, four percent of ad clicks generate a lead and each click costs two euros. It needs 40 leads and 1,000 clicks, giving a media budget of €2,000. Media cost is €50 per lead and €200 per new customer.

The calculation shows which assumptions matter. In the table below, cost per click stays at €2, the media budget at €2,000 and the lead-to-sale rate at 25 percent. If lead quality changes, the sales rate must also be reassessed.

Separate spend paid to Google from other costs

The media budget covers advertising paid to Google. Planning, campaign management, creative assets, measurement implementation and landing-page improvements are separate costs unless the proposal says otherwise. Compare alternatives using total costs over the same period and confirm how VAT is treated.

If specialist work in the example cost an illustrative €400 per month, total cost would be €2,400 and acquisition cost €240 per customer. One-off setup costs need to be included as well. Our article on Google Ads pricing explains the cost components in more detail.

Check demand before committing the budget

A local service, a nationwide online store and a narrow B2B service need different plans. Relevant search volume, competition, service area and seasonality limit how much advertising can be bought productively. Concentrate a small budget on the most important service or product group so you can evaluate results.

Keyword Planner offers search and traffic forecasts for budget planning. These estimates take factors such as budget, bids, seasonality and historical ad quality into account. Use them alongside existing account data. There is no need to spend the entire budget if additional traffic has no profitable purpose.

A daily budget and a charging limit are different

The average daily budget used by most campaigns allows spend to vary by day. When a campaign runs throughout the calendar month with an unchanged budget, the daily charging limit is generally twice the daily budget and the monthly limit is 30.4 times it. With a €30 daily budget, the limits are €60 per day and €912 per month.

Changing the budget changes the limits. The change-day limit uses the highest budget set that day, even if you lower it later. The remaining monthly limit uses the new budget and the remaining calendar days. A campaign total budget is a different budget type for a fixed period: the total cap applies, but there is no equivalent daily cap. The budget type cannot be changed after the campaign has been created.

Agree a test objective and a review point

A test needs a defined spending limit, working measurement and an agreed review point. Specify what qualifies as an acceptable lead, how quickly enquiries will be answered and which evidence will determine whether to continue. This makes it possible to improve the campaign when early results differ from the calculation.

Allow for your normal sales cycle. In a long B2B sales process, this week’s leads do not yet reveal their final customer acquisition cost. Follow leads from the same period as they progress through sales, and distinguish open opportunities from completed deals. No single test duration or conversion count suits every business.

• Verify that a successful booking, order or form submission is recorded accurately and once.
• Record lead quality and sales outcomes consistently throughout the test.
• Agree the budget, review date and corrective actions before launch.

Increase spend when demand and sales capacity support it

A larger budget is justified when current advertising brings customers at an acceptable cost, measurement is reliable and the business can serve more demand. Also check whether relevant demand is being missed. If the problem is a weak offer, a poor landing page or slow sales follow-up, extra budget can amplify those problems.

Evaluate the additional investment separately. A low average acquisition cost does not guarantee that the next customers will cost the same. Document the budget change, monitor cost against sales and allow for the sales cycle before the next decision.

What should a good budget proposal explain?

A good proposal makes its assumptions visible and lets the business assess whether the objective is realistic. Ask for the reasoning behind both media spend and specialist fees. If precise results are promised without demand, conversion or sales data, the calculation needs a clearer explanation.

• Which services, products and regions will receive the budget?
• What evidence supports the cost per click, lead conversion rate and lead-to-sale rate?
• What total customer acquisition cost is acceptable?
• How will lead quality, measurement and actual sales be checked?
• When will spend increase, decrease or be directed to website improvements first?