It’s the question I hear more than any other from personal injury attorneys: “How much should we be spending on ads?”
Most agencies answer with “it depends,” which is technically true and practically useless. Others quote a flat number that has nothing to do with your market, your intake team, or your growth goals.
I prefer a different approach. Instead of starting with a budget and hoping it produces cases, start with the number of cases you want and work backward. With 3 numbers from your own data, you can calculate what your ad spend should be. No guesswork required.
The Formula: Working Backward From Signed Cases
Every paid advertising campaign for a personal injury firm comes down to 3 metrics:
- Cost per click (CPC): what you pay each time someone clicks your ad
- Qualified lead conversion rate: the percentage of clicks that become real, qualified potential clients
- Intake conversion rate: the percentage of qualified leads your firm actually signs
The math works like this. Divide your cost per click by your qualified lead conversion rate, and you get your cost per qualified lead (CPL). Divide that by your intake conversion rate, and you get your cost per signed case (CPA). Multiply by the number of cases you want each month, and you have your ad budget.
Here’s a simple example:
- Your average cost per click is $50
- 10% of those clicks turn into qualified leads, which puts your cost per qualified lead at $500
- Your intake team signs 20% of qualified leads, which puts your cost per signed case at $2,500
If your goal is 5 new personal injury cases per month, your ad spend should be about $12,500 per month, plus management fees.
Put another way, $12,500 buys you roughly 250 clicks. Those 250 clicks produce about 25 qualified leads, and 25 qualified leads produce about 5 signed cases.
That’s it. That’s the conversation every PI firm should be having before they spend a dollar on ads. Now let’s look at each piece, because each one is a lever you can pull.
Step 1: Know Your Cost Per Click
Personal injury keywords are among the most expensive in all of online advertising. Insurance companies, national firms, and lead generation companies all compete for the same searches, and that pushes prices up.
Your CPC depends on a few factors:
- Your market. A click in a major metro can cost several times what it costs in a smaller city.
- Case type. MVA keywords typically cost more than dog bite or slip & fall terms, because the potential case values are higher.
- Search intent. “Car accident lawyer near me” costs more than “what to do after a car accident,” because the person searching is closer to hiring someone.
If you’ve run ads before, pull your actual CPC data from Google Ads. If you haven’t, Google’s Keyword Planner will give you a reasonable starting estimate for your market. Just remember that the estimate is a starting point. Real-world costs often run higher once you’re competing in live auctions.
Step 2: Measure Qualified Leads, Not Just Leads
This is where a lot of firms (and marketing agencies, for that matter) fool themselves. A form fill or phone call is not automatically a lead. In personal injury, a surprising number of inquiries aren’t viable:
- The person wasn’t injured, or the accident was their fault
- They didn’t get treatment
- The statute of limitations has passed
- They already have an attorney
- It’s a different practice area entirely (workers’ comp, criminal, family law)
- It’s spam, a solicitor, or a wrong number
When I say “qualified lead conversion rate,” I mean the percentage of ad clicks that turn into a real potential client you’d want to sign. If your landing page converts 15% of visitors but half of those contacts are unqualified, your true qualified conversion rate is closer to 7.5%. That difference changes your budget math significantly.
Your landing page is one major factor here. A strong PI landing page loads fast on a phone, puts a click-to-call button front and center, speaks directly to the injury the person searched for, and builds trust quickly with reviews, results language that’s compliant with your state’s advertising rules, and ideally a short video of an attorney speaking directly to the viewer. Video is one of the fastest ways to build trust with an injured person who has never met you. Sending paid traffic to your homepage is one of the most common, and most expensive, mistakes I see.
The Problem Most Firms Don’t See: Your Ads Are Optimizing for the Wrong Thing
The other major factor is less obvious, and it’s where I see the most wasted budget.
Google and other ad platforms are very good at finding more of whatever you tell them is a conversion. The problem is that most PI campaigns tell the platform that every phone call or form fill counts as a success. So the algorithm dutifully goes out and finds more calls and forms, including the wrong numbers, the out-of-state inquiries, the workers’ comp questions, and the people who already have a lawyer. On paper, lead volume looks healthy. In reality, a big share of the budget is funding noise.
This is exactly why we built LawAmp Signal, our proprietary intake intelligence platform. It’s something we developed in-house based on almost 15 years of personal injury marketing experience, and it isn’t available anywhere else.
Signal reads what actually happens on every call, form, and chat: the case details, how your intake team handled the conversation, whether the matter fits your specific practice areas, and whether a consultation was scheduled. It combines that information with additional third-party data and feeds it back to the ad platforms, so their algorithms learn the difference between a quality case and a junk inquiry. Over time, campaigns that produce real cases get more of your budget, and the ones that produce noise get less.
In terms of the formula, this is how you raise your qualified lead conversion rate without paying more per click. Better signals in, better leads out, and a lower cost per qualified lead.
Step 3: Be Honest About Your Intake Conversion Rate
This is the number most firms don’t want to look at, and it’s often the one with the most room for improvement.
You can run perfect ads to a perfect landing page and still lose money if your intake process is slow or inconsistent. Personal injury prospects are usually contacting more than one firm. The firm that responds first, and responds well, very often gets the case.
Common intake leaks include:
- Calls going to voicemail after hours or on weekends
- Web form submissions that sit for hours before anyone follows up
- Intake staff who treat callers like a checklist instead of a person who just got hurt
- No follow-up process for leads who don’t sign on the first call (it takes 5-12 follow-ups to sign most cases)
The challenge is that most firms can’t actually see these leaks. They know how many cases they signed, but not how many good opportunities slipped away or why. Because LawAmp Signal evaluates how intake handled each conversation and whether a consult was booked, it gives firms a clear view of where qualified leads are being lost, so you can coach your team with real examples instead of guesses.
If your intake team signs 20% of qualified leads, improving that to 30% has the same effect on your cost per case as cutting your click costs by a third. And unlike click costs, intake is something you fully control.
Step 4: See How Each Lever Changes Your Budget
Here’s where the math gets interesting. Using the same goal of 5 signed cases per month, look at what happens when you improve just one or two numbers:
| Scenario | CPC | Qualified Lead Rate | Intake Rate | Cost Per Case | Monthly Spend for 5 Cases |
|---|---|---|---|---|---|
| Starting point | $50 | 10% | 20% | $2,500 | $12,500 |
| Better lead quality | $50 | 15% | 20% | $1,667 | $8,333 |
| Better intake | $50 | 10% | 30% | $1,667 | $8,333 |
| Both improved | $50 | 15% | 30% | $1,111 | $5,556 |
Same click costs. Same number of cases. Less than half the spend.
This is why I tell firms that “how much should we spend?” is really 3 questions. Before you increase your budget, make sure you aren’t pouring money into a leaky funnel. Sometimes the best way to get more cases is to improve lead quality and intake first, then scale.
These numbers are illustrative. Every market and every firm is different, and no one can promise a specific improvement. But the direction is consistent: small gains in lead quality and intake compound quickly.
Step 5: Make Sure the Number Makes Sense for Your Firm
Once you know your cost per case, compare it against what a typical case is worth to your firm in fees. You don’t need a complex spreadsheet for this. The question is simple: does your cost to acquire a case leave you comfortable room for profit, given the types of cases your ads are bringing in?
If the answer is yes, you have a campaign worth scaling. If the answer is no, go back to the 3 levers above, or look at whether your ads are targeting the right case types.
Keep in mind that personal injury has a built-in lag. Cases you sign this month may not resolve for many months, sometimes longer. Judge your campaigns by signed cases and cost per case in the short term, and by fee revenue over the long term. The standard we use, and that the industry uses, is that your all-in marketing cost per case should be less than 15% of case value.
A Few Practical Realities
Budget too small to learn. If your daily budget only buys a handful of clicks, it can take months to collect enough data to know what’s working. An underfunded campaign often looks like a failed campaign when it simply hasn’t had a fair test.
Give it time. The first 60 to 90 days of any new campaign are largely about gathering data and refining targeting, keywords, and landing pages. Judging a PI campaign on its first 2 weeks usually leads to bad decisions. In general, the more you spend, the faster the campaign learns as long as it’s being fed the right data.
Track what matters, not just what’s easy. This formula only works if you have real numbers. Basic call and form tracking tells you how many contacts you received. It doesn’t tell you which ones were actual cases. That’s the gap intake intelligence fills, and it’s the difference between measuring activity and measuring results.
Don’t forget management. The spend figure from the formula is what goes to Google (or another ad platform). Professional campaign management is a separate cost, and a good manager should be improving your CPC, conversion rates, and lead quality over time, which lowers your cost per case.
Paid Ads Are One Piece of the Picture
Paid search gets you in front of people who need a lawyer right now, and it’s the fastest way to generate cases. But the strongest personal injury firms don’t rely on ads alone.
Search Engine Optimization (SEO), GEO and AEO (AI Search) build organic visibility that compounds over time and reduces your dependence on paid clicks. A strong review profile improves both your ad performance and your conversion rates. And consistent video content on social media builds the kind of familiarity and trust that makes someone call your firm when they’re hurt, instead of a competitor’s.
Over time, a healthy mix of organic growth and paid advertising lowers your blended cost per case, which is the number that ultimately matters.
The Bottom Line
So, how much should your personal injury firm spend on ads? Here’s the real answer: enough to hit your case goals, based on your actual numbers.
Figure out your cost per click. Measure your qualified lead rate. Be honest about your intake conversion rate. Then work backward from the number of cases you want. The math will tell you your budget, and more importantly, it will show you exactly where to improve.
Every market is different, and no one can guarantee a specific number of cases. But when you approach your ad budget with real data instead of guesswork, and make sure your ad platforms are optimizing for real cases instead of raw lead volume, you get far more out of every dollar.
If you’d like help running these numbers for your firm, or want to see how LawAmp Signal could improve the quality of leads your campaigns produce, let’s talk. At LegalScapes, we’ve been helping personal injury firms grow since 2012, and this is exactly the kind of strategic conversation we have with our clients every day.
