Google will take any budget you give it. Whether that budget can produce customers at a price you can live with is arithmetic, and most businesses run the campaign first and the arithmetic never. This calculator does it in ten seconds: what a lead really costs you, what a customer really costs you, and whether the math closes before you spend a shekel. Runs in your browser, nothing stored, no email.
Most service categories run $2-5. Legal, insurance, big-metro home services run far higher.
A decent landing page converts 3-7% of clicks into calls or forms.
Typical service businesses close 1 in 3 to 1 in 5 inquiries.
First job value, or lifetime value if customers return. Be honest, not hopeful.
Ad spend only, before any management fees.
How the math works
The chain is short and unforgiving. Cost per lead is your click price divided by your landing page conversion rate: at $4 clicks and 5% conversion, a lead costs $80. Cost per customer divides that by your close rate: closing 1 in 4 makes the customer $320. Your budget divided by that number is your monthly customer count, and comparing customer cost to customer value is the whole worth-it question.
Every input is improvable, and they don’t improve equally. Halving your click price is hard; doubling a 2.5% landing page to 5% is a weekend project that halves your cost per customer. The conversion inputs are where small businesses find the cheap wins, which is why the calculator asks for them instead of hiding them.
Reading your result honestly
A customer cost under a third of customer value: healthy, scale carefully. Between a third and full value: workable if customers return or refer, fragile if they don’t. Above customer value: stop, the channel is upside-down at these numbers, and a bigger budget just buys the loss faster. Fix the conversion steps or the offer first, or spend the budget on channels that compound; the ranked alternatives are in our customer sources breakdown.
One more check before trusting any of it at low budgets: the learning floor. Below roughly $500/month most accounts generate too few conversions for Google’s bidding to optimize, so real results come in streaky and worse than the math predicts. The full budget logic, including the working minimum and the spending order, is in the Google Ads budget guide, and the settings that quietly ruin these numbers, wrong searches, loose matching, leaky geography, are in the wrong-searches fix.
Frequently asked questions
What’s a good cost per lead for Google Ads?
There’s no universal number; it’s relative to customer value. $80 per lead is excellent for a $2,000 job and catastrophic for a $150 one. Run your own chain rather than chasing benchmark averages from unrelated industries.
What’s a realistic conversion rate for a landing page?
3-7% of clicks becoming calls or form fills is a reasonable range for service businesses with a decent page. Under 2% usually means a page problem, not an ads problem: slow load, buried phone number, or an ad promise the page doesn’t repeat.
How much should I budget for Google Ads?
Enough to buy the leads your goal requires at your cost per lead, with $500/month as the practical floor for the algorithm to learn. Work backwards: customers wanted × cost per customer = required budget.
Why are my real results worse than the calculator?
Usually one of three leaks: budget spent on irrelevant searches, clicks from outside your service area, or a landing page converting below what you assumed. Check the search terms report first; it’s the honest page.
Does this math include management fees?
No, it’s ad spend only. If you pay for management, add the fee to the monthly budget when comparing customer cost to value. Under ~$1,000/month spend, fees usually eat the math; past $1,500-2,000 a good manager typically recovers more than they cost.
Want a second pair of eyes on your numbers, or an honest “this channel isn’t for you”? Send them over. Both answers are free.