“How much should I spend on Google Ads?” It’s the first question almost every new client asks me. And honestly, there’s no universal answer — but there is a framework that works. After managing ad budgets for 25+ clients across med spas, law firms, automotive dealerships, and medical practices over 20+ years, here’s how I think about it.
The Wrong Way to Set a Budget
Most small businesses set their Google Ads budget by picking a number that feels comfortable — $500/month, $1,000/month — without any connection to what it actually costs to get a lead in their industry. That’s backwards. The right approach starts with your desired outcome and works backward to a budget.
The Right Framework: Work Backward From CPA
Here’s the math:
- What’s a customer worth to you? (Lifetime value or average transaction)
- What’s an acceptable cost per acquisition (CPA)? (Typically 10-30% of customer value)
- What’s your expected conversion rate? (Landing page + offer quality)
- What does a click cost in your industry? (Check Google Keyword Planner)
Example for a med spa:
– Average patient value: $500/year
– Acceptable CPA: $75 (15% of value)
– Expected conversion rate: 8% (good landing page)
– Average CPC for “botox san diego”: $6
– Clicks needed per conversion: 100/8 = ~12.5 clicks
– Cost per conversion: 12.5 x $6 = $75
– Budget for 20 new patients/month: 20 x $75 = $1,500/month
This is a simplified model, but it illustrates the principle: budget should be derived from your business math, not guessed.
Industry CPC Benchmarks (2026)
| Industry | Avg CPC Range | Suggested Min Monthly Budget |
|---|---|---|
| Legal (personal injury) | $15–$80 | $3,000–$5,000+ |
| Med Spa / Aesthetics | $4–$15 | $1,500–$3,000 |
| Medical / Healthcare | $6–$25 | $2,000–$4,000 |
| Automotive (dealership) | $3–$12 | $2,000–$5,000 |
| Home Services | $5–$20 | $1,500–$3,000 |
| Retail / Ecommerce | $0.50–$5 | $1,000–$2,000 |
These ranges are for competitive markets. San Diego CPCs trend 15-25% higher than national averages in most categories.
Why “Just $500/Month” Usually Fails
I hear this often: “I’ll start small and scale up if it works.” The problem is that $500/month in a competitive service category buys you maybe 50-100 clicks. That’s not enough data to optimize. Google’s Smart Bidding algorithms need 30+ conversions per month to function properly. At $500, you might get 2-3 conversions — not enough to know if your campaign is working or just having a slow week.
The minimum viable budget for most local service businesses in a competitive city like San Diego is $1,500-$2,000/month. Below that, you risk creating a false negative — the campaign looks like it doesn’t work when really it just doesn’t have enough data.
How to Allocate Your Budget Across Campaigns
Once you have a monthly budget, here’s how I typically split it for a new account:
- 70-80% — Core service Search campaigns (highest intent, highest ROI)
- 10-15% — Remarketing (Display or RLSA for past visitors)
- 10% — Testing budget (new campaigns, new keywords, new offers)
Don’t spread too thin. A focused $2,000 campaign on two service keywords will outperform a diluted $2,000 campaign spread across 10 keyword themes every time.
When to Scale
Scale your budget when:
- Your campaigns are converting at or below your target CPA
- You have impression share data showing you’re losing clicks due to budget (check the “Search Impression Share Lost to Budget” column)
- You’ve achieved 3+ months of consistent results
Don’t scale when your CPA is above target. Fix the conversion problem first — more budget on a broken campaign just burns money faster.
Budget Seasonality
Plan for seasonal demand swings. For med spas, budget up for Valentine’s Day and pre-summer. For law firms, consider year-round consistency since legal needs don’t peak seasonally. For retail, Black Friday and holiday seasons require 2-3x your normal budget. Build a 12-month budget plan at the start of the year.
One More Thing: Management Fees
If you’re working with an agency (like mine), management fees are separate from your ad spend. A typical arrangement is 10-20% of ad spend per month, or a flat fee. Your $2,000/month budget goes entirely to Google — management is on top. Make sure you understand this distinction before you sign anything.
Want to understand where your current budget is going? Start with a Google Ads account audit — I walk through exactly how to find budget waste and reallocate to better performers. And if you want to understand the full competitive landscape before you set a budget, my beginner’s guide to Google Ads is the right starting point.
Frequently Asked Questions
What is the minimum budget to run Google Ads effectively?
My practical minimum for seeing meaningful results is $1,500-$2,000 per month. Below that in most competitive local markets, campaigns will have too little data for Smart Bidding to optimize, and you’re competing against advertisers with 10x your budget for the same keywords. The $500/month Google Ads budget I see many small businesses try rarely generates enough volume to test what’s working. Budget determines data velocity — more budget means faster learning.
How do I calculate my ideal Google Ads budget?
Start with your target leads per month and work backwards. If you need 20 leads/month, your conversion rate is 5%, and average CPC is $8, you need 400 clicks x $8 = $3,200/month. Adjust based on actual conversion data once campaigns are running. I recalculate this math for every new client before we set a starting budget, then revisit it at the 60-day mark once we have real account data to plug into the formula.
Does spending more on Google Ads always get better results?
No. Increasing budget only improves results if your account is already converting efficiently. Pouring more money into a broken account wastes more money faster. Before increasing budget, verify conversion tracking is accurate, ads are converting at a healthy rate, and Quality Scores are above 5. Once those fundamentals are in place, budget increases typically scale proportionally to results. Budget without structure is just burning money faster.
Should I start with a small budget and scale up?
Yes. Start with enough budget to generate meaningful data — at least 10 clicks per day, meaning your daily budget should be at least 10x your average CPC. For a $5 average CPC, that’s $50/day minimum. Run for 30-60 days, identify which keywords, ads, and landing pages convert, cut the non-performers, and scale budget into what’s working. This approach minimizes initial waste and builds a stronger foundation for scaling.
What’s the difference between daily budget and monthly budget in Google Ads?
Google Ads uses daily budgets but can spend up to 2x your daily budget on high-traffic days, compensating with lower spend on lighter days. Over any 30-day period, Google will never charge more than your daily budget x 30.4 days. So a $100 daily budget means a maximum monthly spend of approximately $3,040. The monthly spend fluctuates, but the 30-day cap provides budget predictability for cash flow planning.
Looking for more Google Ads strategies? Read my guide on How to Lower Your Cost Per Click, explore my Google Ads management services, or get in touch to talk through your account. I manage paid search for 15+ active clients across San Diego.
