The short version
- Pull the monthly searches and the top of page bid range for your services and towns from Google's Keyword Planner.
- Multiply cost per click by clicks per lead and leads per job to get a cost per job, then check it against what a job earns you.
- Divide the monthly number by 30.4 to set the daily budget, because that is how Google paces spend across a month.
How much should I spend? It is the right first question about Google Ads, and the honest answer is a method, not a number. A roofer in Tacoma and a plumber in Beaverton are buying different searches, against different competitors, for jobs worth very different amounts. A number that fits one of them would be a guess for the other.
This is the method I use before a campaign goes live. It takes four numbers, a few lines of multiplication, and an honest look at what a job is worth to you. If you are new to how search ads work, start with my guide to Google Ads for contractors and come back.
Start with the searches, not the budget
A budget is a ceiling on spending. It does nothing if not enough people in your towns search for the work you do. So the first question is how many searches there are, and what advertisers pay to show up on them.
Google answers both in Keyword Planner, a tool inside Google Ads. To get keyword ideas you need an account with billing information entered, as Google notes on its page about how to use Keyword Planner (opens in a new tab).
Type in the services you sell the way a homeowner would say them. Roof repair, roof replacement, gutter replacement. Then set the location to the towns you actually serve, say Renton, Kent, and Auburn, instead of the whole state. For each keyword, Keyword Planner shows two numbers that matter for a budget, and Google explains both on its Keyword Planner forecasts page (opens in a new tab).
- Average monthly searches. How many times people searched that keyword and its close variants, in the locations you picked. By default it is averaged over 12 months, and you can look at it month by month to see your busy and slow seasons.
- Top of page bid, low and high. Google describes the low end as roughly the 20th percentile of what advertisers paid to show at the top of the page, and the high end as roughly the 80th percentile, based on the last 30 days.
Take these as estimates, and Google says so itself. The search numbers are rounded, forecasts get less accurate for small areas, and a brand new account gets forecasts built from averages across all advertisers until it has its own history. That is still far better than a number picked because it sounded safe.
The four numbers behind every budget
A contractor's budget comes down to four numbers. Two come from Google, and two come from you.
| Number | Where it comes from | What it tells you |
|---|---|---|
| Searches a month | Keyword Planner, for your services in your towns | How much room there is to spend |
| Cost per click | The top of page bid range in Keyword Planner | What each visit to your page costs |
| Clicks per lead | Your site's history, or a planning guess until the ads run | How many visits it takes to get one call or quote request |
| Leads per job | Your own records | How many estimates it takes to win one job |
Cost per click
Plan with the high end of the range for the keywords that matter most. The low end is roughly the 20th percentile, so planning on it assumes you will pay less than about four out of five advertisers did for the same spot. Some keywords will come in under your plan. It is better to find that out after launch than to find the opposite.
Clicks per lead
This is the number nobody knows before the ads run. If your site already gets quote requests, your stats dashboard gives you a starting point. If not, pick a planning guess, write it down as a guess, and replace it with the real number once calls and quote requests start coming in from the ads.
Leads per job
This number comes from you. Look at the last few months. How many estimates did you give, and how many turned into signed jobs? A shop that wins one job for every three estimates needs a different budget than one that wins one in six.
The math, with made up numbers
Every number in this section is invented for the example. None of them is a typical cost for any trade or town, so do not copy them. Put your own numbers in their place.
Say Keyword Planner shows about 1,000 searches a month for your main services in your towns, and you plan on a cost per click of $20. Say one in every 10 clicks turns into a call or a quote request, and you win one job for every 3 leads.
- Cost per lead. $20 a click times 10 clicks is $200 for each lead.
- Cost per job. $200 a lead times 3 leads is $600 in ad spend for each job you win.
- Monthly spend. If you want 4 more jobs a month from ads, that is 4 times $600, or $2,400 a month.
- Clicks needed. $2,400 divided by $20 is 120 clicks a month.
- Room in the market. 120 clicks out of about 1,000 searches is a lot to ask for. Keyword Planner's forecast shows how many clicks your keywords are likely to get at a given spend, so check whether your towns can give you 120 before you plan on it.
Step five is the one people skip. If the forecast says your towns will only give you 60 clicks at that cost, the plan needs more towns, more services, or a smaller goal. Money cannot buy searches that do not happen.
Check the math against the job
A cost per job only means something next to what the job earns. Compare it with your gross profit on a typical job, not the invoice total.
With the same made up numbers, $600 of ad spend per job is a very different decision on a full roof replacement than on a small repair. That is why I split campaigns by service. A replacement campaign and a repair campaign each get their own budget, their own ads, and their own landing page, and each one has to earn its keep on its own numbers.
The same check tells you when not to run ads for a service. If the cost per job comes out higher than what the job leaves you after materials and labor, no amount of tuning makes that campaign worth it. Put the money on the services where the math works, and let the rest come from referrals, your Google Business Profile, and your site.
Turning a monthly number into a daily budget
Google Ads budgets are set per campaign as an average daily amount. Google's page on spending limits (opens in a new tab) spells out two rules. On any single day a campaign can spend up to twice its average daily budget, to catch busy days. Over a month it will not charge more than 30.4 times the daily budget, which is 365 days divided by 12 months.
So to set the daily budget, divide the monthly number by 30.4. With the example above, $2,400 a month divided by 30.4 is about $79 a day.
One detail catches contractors who only want ads on weekdays. The same Google page says that when a campaign uses an ad schedule, the system still paces toward the full 30.4 times the daily budget, however many days the campaign is scheduled to run. If you turn the ads off on weekends, set the daily budget from the monthly number anyway. Do not raise it to make up for the days off, or the month will run over your plan.
The ad spend goes from your card to Google. It is never part of my fee.
What changes after launch
The plan is built on estimates, and two of the four numbers are guesses until the ads run. After launch the real numbers come in. You see the actual cost per click, the calls and quote requests each campaign produced, and which searches spent the money.
That is when the budget gets its first honest test. If the real cost per lead comes in under the plan, the campaign has room to grow, as long as the searches are there. If it comes in over, the fix is usually in the search terms and the landing page before it is in the budget. A campaign that spends on job seekers and do it yourself searches has a cost per lead problem that more money will only make bigger.
Give it time before you judge. A few days of clicks is not enough to tell a good campaign from a bad one, and one slow week in November says little about March.
How I send you the numbers before launch
Before any campaign I build goes live, I pull the search volume and the cost per click for your trade and your towns from Keyword Planner and send you the numbers in writing. You see what the market looks like before you spend anything on clicks, and you set the daily budget yourself.
The campaign build is $1,500, paid in full up front, and it goes live within a week in your own Google Ads account. Management is $1,000 a month, month to month. I read every search term twice a week and write a report by hand every week. The ad spend is separate and goes from your card to Google, usually $50 to $110 a day. I run Google Ads only on a site I built, for contractors whose average job is over $10,000. The details are on the Google Ads management page, and you can send your trade and towns on the start page.
