"What should we be spending on Google Ads?" is usually the first question a business owner asks — and the honest answer is that anyone who quotes you a number before asking about your market, your margins, and your close rate is guessing. But there is a reliable way to calculate it, and it starts with what a click actually costs in your industry.
What clicks cost in 2026
Across US search campaigns, average cost per click sits in the $2–$7 range for most industries. But averages hide the spread that actually matters for budgeting:
- E-commerce and retail: often $1–$3 per click
- Home services (HVAC, roofing, plumbing): $15–$40 per click in competitive metros
- Legal, insurance, and finance: $30–$80+ per click for high-intent terms
- B2B and professional services: typically $5–$15 per click
This is why a $500/month budget can be perfectly workable for one business and functionally useless for another. In a market where clicks cost $30, that budget buys around 16 clicks a month — not enough data to learn anything, let alone convert consistently.
The minimum viable budget: enough to learn
Your first budget's job is not profit. It's data. Google's bidding algorithms and your own decision-making both need conversion volume to work with, and the practical floor is roughly 20–30 conversions per month per campaign.
Work it backward: if your landing page converts 5% of clicks into leads and your average CPC is $6, a conversion costs about $120. Thirty conversions means a working budget of around $3,600/month for that campaign. If that number is far beyond reach, the answer usually isn't "spend less everywhere" — it's narrowing to fewer keywords, tighter geography, or a single service line until the math works.
The most expensive Google Ads budget is one that's too small to generate learnings but large enough to feel like real money.
A working-backward formula
Instead of starting from what you can afford, start from what a customer is worth:
- Customer value: what is a new customer worth to you — first sale, or lifetime value if they repeat?
- Allowable cost per acquisition: how much of that value can you spend to win them and still hit your margin?
- Lead-to-customer rate: if you close 25% of leads, your allowable cost per lead is a quarter of your allowable CPA.
- Conversion rate: divide cost per lead by your landing page conversion rate to get your maximum affordable CPC.
Now compare that maximum CPC against what your market actually charges. If the numbers work, Google Ads can scale profitably. If they don't, no amount of account optimization will fix the underlying economics — you fix the close rate, the offer, or the landing page first.
How budgets should change over time
Months 1–2: testing
Expect this spend to underperform, on purpose. You're buying search term data, testing match types, and finding out which services and geographies actually produce leads. Judge it on learnings, not return.
Months 3–6: consolidation
Cut what didn't convert, feed what did. Cost per lead typically drops 20–40% in this phase without spending a dollar more — this is where the waste we covered in why most Google Ads accounts waste budget either gets removed or gets institutionalized.
Month 6+: scaling
Only now does "spend more" become the right lever — and only into campaigns with proven unit economics. Scaling a broken account just buys more of the same problem.
Signs your budget is wrong (in either direction)
- Your campaigns are limited by budget before noon — you're either underfunded or targeting too broadly
- You have fewer than 15 conversions a month — the algorithm is flying blind
- Impression share is above 90% and leads have plateaued — more budget won't buy more demand; you've saturated the market you're targeting
- You can't say what a lead costs you — a budget without conversion tracking isn't a strategy, it's a subscription
So what's the actual number?
For most US service businesses entering a moderately competitive market, a realistic starting range is $1,500–$5,000/month in ad spend — enough to generate meaningful data within 60 days. In high-CPC verticals like legal or home services in major metros, competitive entry often starts at $5,000–$10,000/month, and pretending otherwise wastes whatever smaller amount gets spent instead.
The number that matters, though, is yours: your customer value, your close rate, your market's click costs. Run the formula above and you'll have a defensible budget in twenty minutes — or we can run it with you, against real search volume and CPC data for your market, before you commit a dollar of spend.