Cost per signed case is your total marketing spend divided by the number of matters you actually retained in the same period. A firm that spent $20,000 and signed 8 cases is at $2,500 a case.
That’s the whole formula, and almost every firm I talk to gets it wrong anyway. Not because the division is hard. Because both numbers are harder to pin down than they look, and the period you divide across is usually the wrong one.
Most personal injury firms can tell you their cost per lead to the dollar. Very few can tell you what a signed case costs them. That gap is where marketing budgets go to die.
The four numbers you need
Every honest cost-per-case calculation rests on four figures:
- What you spent
- How many leads that produced
- How many of those leads signed
- Over what window you’re measuring
Most firms have the first two sitting in a dashboard. The third lives in the case management system and rarely gets connected back to the first. The fourth almost nobody thinks about at all, and it’s the one that quietly ruins the math.
Getting the definitions right
The chain from spend to signature runs through five stages, and each one needs a definition your whole team agrees on. Write them down. If your agency’s definition of a lead and your intake manager’s definition of a lead are different, every report you’ve ever received has been describing something other than what you thought.
Marketing spend is every dollar that went toward producing inquiries in the period. More on what belongs in that bucket below, because it’s where firms disagree most.
A lead is any inbound inquiry that reached your firm. Form fill, phone call, chat, text. Bots and wrong numbers don’t count, and if you’re not filtering those out your CPL is flattering you.
A qualified lead is an inquiry that met your case criteria. Right practice area, plausible liability, injury present, within statute, not already represented. Your criteria, stated in advance, applied consistently.
A consultation is a real conversation with someone who can evaluate the matter. Not a voicemail. Not a scheduled appointment nobody showed up for.
A signed case is an executed retainer. Not a verbal yes, not a sent engagement letter sitting unsigned in someone’s inbox.
Those distinctions sound pedantic until you watch two people in the same firm produce conversion rates twenty points apart because one counts sent retainers and the other counts executed ones.
The mistake almost everyone makes
Here’s the one that costs real money.
A case you signed in August probably came from a lead that arrived in June. Maybe May. Somebody got hurt, took a few days to start looking, filled out a form, talked to your intake team, thought it over, talked to their spouse, called two other firms, then came back and signed. Meanwhile you paid for that lead eight weeks ago.
Divide August’s spend by August’s signatures and you’ve just compared two unrelated things. That’s how most monthly marketing reports are built, and in a growing account it makes performance look worse than it is. In a shrinking one it makes performance look better. Either way you’re steering off a broken instrument.
The fix is cohort tracking. Group leads by the month they arrived, then follow that specific group forward until it stops producing signatures. June’s spend gets measured against June’s leads and whatever those June leads eventually became, regardless of what month the retainer got signed.
It takes a field in your CRM and a little discipline. Tag every lead with its arrival month and its source, and stop letting close date drive the report. Most case management systems can do this already. Almost nobody turns it on.
One practical consequence: your most recent 60 to 90 days will always look bad, because those cohorts haven’t finished converting. Don’t panic and don’t let anyone use it against you. Read cohorts that have had time to mature.
We’re watching this play out in real time on one of our own accounts. As of the numbers I have, a firm we run personal injury campaigns for signed 2 PI cases in July against $3,493 in PI-specific media spend that same month, which works out to $1,746 a case if you divide the two. Except 6 of the 8 PI calls logged that month are still marked outcome unknown. If two more sign, cost per case drops by roughly a third. The $1,746 isn’t wrong. It’s just not finished yet, and won’t be for another month or two.
What actually counts as marketing spend
Ask three people what belongs in the numerator and you’ll get three answers. It matters more than you’d think.
Say you spend $10,000 a month on Meta. Here’s the same campaign counted two ways, using illustrative numbers to show the mechanics:
| Line item | Media only | Fully loaded |
|---|---|---|
| Ad spend | $10,000 | $10,000 |
| Agency or management fee | n/a | $3,000 |
| Call tracking, CRM, landing page tools | n/a | $400 |
| Intake staff time attributable to these leads | n/a | $2,000 |
| Total | $10,000 | $15,400 |
| Cases signed | 7 | 7 |
| Cost per signed case | $1,429 | $2,200 |
Same campaign, same seven cases, and the number moved 54 percent depending on where you drew the line.
Neither column is wrong. They answer different questions. Media-only tells you whether the channel is working. Fully loaded tells you what a case genuinely costs your firm, which is the number you need when you’re deciding whether to hire another attorney. Pick one, write down which one you picked, and use it consistently. The damage comes from switching between them without noticing.
A worked example
Illustrative numbers, but the structure is what matters. Run your own through the same steps.
You spend $10,000 in a month on Meta at a $250 cost per lead.
| Stage | Count | Rate | Running cost |
|---|---|---|---|
| Ad spend | $10,000 | n/a | n/a |
| Leads | 40 | $250 CPL | $250 per lead |
| Qualified leads | 20 | 50% of leads | $500 per qualified lead |
| Consultations held | 14 | 70% of qualified | $714 per consult |
| Signed cases | 7 | 50% of consults | $1,429 per case |
Seven cases from forty leads is a 17.5 percent lead-to-signature rate. If your average attorney fee runs around $8,500, those seven cases represent roughly $59,500 in fees against $10,000 in media. Just under six times return, with media consuming about 17 percent of fee revenue.
Now watch what happens if only the qualification step changes. Same spend, same CPL, same everything downstream:
| Qualified rate | Signed cases | Cost per signed case |
|---|---|---|
| 30% | 4 | $2,500 |
| 40% | 6 | $1,667 |
| 50% | 7 | $1,429 |
| 60% | 8 | $1,250 |
Case counts are rounded to whole cases, since nobody signs four tenths of a retainer. The media buy is identical across all four rows. What separates them is whether the ads are reaching people with real cases and whether intake is measuring that correctly. Twice the cost per case, same ad account.
This is why I push clients on intake before I push them on creative. Getting a cost per lead down 20 percent is real work and takes genuine media skill. Moving a qualified rate from 30 to 50 percent is usually a scripting and staffing problem, and it does more.
When your volume is too low to read
Small firms hit a wall here, and it’s worth being honest about it rather than pretending the math scales down.
We run MVA campaigns for a firm in Montana. Over the life of that account we’ve spent $5,158 and produced 9 website leads, of which 2 signed. That’s a 22 percent lead-to-signature rate and a $2,579 cost per signed case, and I wouldn’t build a strategy on either figure.
At nine leads, one case going the other way moves your sign rate from 22 percent to 11 percent or 33 percent. Same campaign, same operations, completely different story, decided by whether one guy’s brother-in-law happened to be a lawyer.
If you’re signing fewer than about five cases a month, monthly reporting is noise. Do this instead:
- Report on rolling 90-day windows rather than calendar months
- Track the leading indicators that move faster than signatures: response time, contact rate, qualified rate, consult show rate
- Give a channel at least two full quarters before you decide anything
- Watch direction rather than absolute numbers until you’ve got enough cases to make a rate mean something
Leading indicators are the useful part. Response time and contact rate move within weeks and they predict where your signature rate is heading long before you’ve got enough cases to calculate it.
What to do this week
Four things, in order.
Pull your last 180 days of spend by channel. Media plus fees plus tools. Decide now whether you’re counting intake labor and write the decision down somewhere.
Export every lead from the same period with its arrival date and source. If your CRM can’t produce that, that’s your first problem and it’s bigger than your cost per lead.
Match the signed cases back to those leads by arrival cohort, not close date. Cases from the last 60 days won’t have finished converting, so exclude the most recent two months from your rate calculations.
Calculate the rate at every stage, not just the endpoint. Lead to qualified, qualified to consult, consult to signature. One of those three numbers is dragging the rest down, and it’s usually not the one you’d guess.
If you can’t complete step two, the fix isn’t a better media buy. It’s instrumentation, and everything else has to wait for it.
Frequently asked questions
What is cost per signed case? Total marketing spend divided by the matters retained in the same period. For personal injury it typically runs 7 to 20 times the cost per lead, depending mostly on how well intake performs rather than how well the ads perform.
What is a good cost per signed case for a personal injury firm? It depends on your average fee. A useful frame is cost per case as a percentage of the fee it produces. Many firms target somewhere under 25 to 30 percent, though a firm chasing growth may reasonably accept more in exchange for volume.
Should I include agency fees and staff time? Include them if you want to know what a case truly costs your firm. Exclude them if you want to know whether a channel is working. Both are legitimate. What breaks the analysis is switching between the two without saying so.
How do I handle the lag between spend and signature? Group leads by the month they arrived and follow that cohort forward until it stops producing signatures. Never divide this month’s spend by this month’s signed cases. Exclude your most recent 60 to 90 days from rate calculations, because those cohorts are still converting.
My firm only signs two or three cases a month. Can I still use this? Yes, but not monthly. Use rolling 90-day windows and lean on leading indicators like response time, contact rate, and qualified rate, which move fast enough to tell you something before your case volume can.
Why doesn’t my agency report cost per signed case? Usually because they can’t see it. The signature happens in your case management system and the spend happens in the ad platform, and unless somebody deliberately connects the two, nobody holds both halves. Ask whether your signed case data is being fed back into Google and Meta. In most law firm accounts, it never has been.
The short version
Cost per lead tells you whether your ads are cheap. Cost per signed case tells you whether your firm is making money, and the two frequently point in opposite directions.
The calculation is easy. Getting clean inputs is the work, and most firms discover partway through that they can’t trace a signed case back to the lead that produced it. That discovery is worth more than the number would have been.
If you want a second set of eyes on your numbers, that’s the audit we run.