ROAS calculator and Google Ads budget planner
Work out what your ads need to return to make money, and what you would need to spend to win the number of jobs you want, so you can plan before you spend a penny.
An example figure. Use your own from Google Ads, or the top-of-page bid range Google's free Keyword Planner shows for your main search.
Depends mostly on your landing page. Below 3% usually means the page is the problem.
What is left after materials and labour, before ad spend.
What it would take
On these numbers each job costs £139 to win and you keep £200 from it, so the ads pay for themselves. The number that moves this most is the share of clicks that enquire.
Not sure your numbers are right? A free Google Ads audit shows where the budget is actually going.
How much does Google Ads cost for a small business?
There is no set price. You choose a daily budget and pay each time someone clicks, and what a click costs is decided by an auction against everyone else bidding on the same search in the same area. So the honest answer depends on three things.
What a click costs for your searches. Urgent searches cost the most, because every click is someone ready to book: an emergency callout search usually costs more than a planned-work one in the same trade. Find yours in Google Keyword Planner, or in your account if you already run ads.
How many clicks become enquiries. This is set by the page people land on, and it changes the budget more than anything else.
How many jobs you need. Put all three into the budget planner above and it gives you a monthly figure to work from.
The formulas, with a worked example
ROAS = revenue from ads ÷ ad spend. A plumber who spends £600 in a month and wins £2,400 of work from it has a ROAS of 4x.
Break-even ROAS = 1 ÷ profit margin. If half of every job is profit, break-even is 2x. That plumber at 4x is comfortably profitable: £1,200 of profit, less £600 of ads, leaves £600.
Budget = jobs wanted ÷ win rate ÷ enquiry rate × cost per click. Ten jobs, winning three in ten enquiries, with six in a hundred clicks enquiring, at an example £2.50 a click: 10 ÷ 0.3 ÷ 0.06 × £2.50 is about £1,389 a month.
The number with the biggest effect is the share of clicks that enquire. Double it with a better landing page and the same ten jobs cost half as much. That is why we usually fix the website before spending on ads.
Questions, answered
Return on ad spend. It is the revenue your ads brought in divided by what you spent on them. Spend £1,000 and win £5,000 of work and your ROAS is 5x, or 500%. It measures revenue, not profit, which is why break-even ROAS matters.
The ROAS at which your ads exactly pay for themselves once the cost of doing the work is taken out. It is 1 divided by your profit margin. At a 50% margin you need 2x to break even; at a 25% margin you need 4x. A business with thin margins can have a ROAS that looks healthy and still lose money on every sale.
Whatever comfortably beats your break-even ROAS. There is no universal good number, because it depends entirely on your margin. For most trades and local services, where margins are reasonable and a customer can come back for years, anything above break-even is worth having, and the lifetime value of a customer makes it better still.
You set the budget, so there is no fixed price, but what you need to spend depends on what a click costs in your trade and how well your website turns clicks into enquiries. This page explains how to find what a click costs for your own searches. The budget planner works the rest out from the number of jobs you want.
If you already run Google Ads, it is the Avg. CPC column in your account. If you do not, Google Keyword Planner is free with a Google Ads account and shows a top-of-page bid range for any search. Use the middle of that range for planning. Prices vary by town, by time of day and by how many competitors are bidding.
ROAS compares revenue to spend. CPA, cost per acquisition, is what you pay for each enquiry, call or sale. Service businesses often find CPA easier to work with, because the value of an enquiry is not known until the job is quoted and won.
Turn the numbers into a plan
See where your budget really goes
A free, plain-English review of your Google Ads account. No charge, no obligation.
Grade the page your ads land on
Find out whether your website is turning clicks into enquiries, with five specific fixes.
How we run Google Ads
Management for local businesses across Gloucestershire, from £150 a month.