How to Calculate Cost per Signed Case from Purchased Leads

You bought leads. Some turned into consultations. A few turned into signed clients. But do you actually know what each signed case cost you? Most law firm owners track lead spend in one column and revenue in another, then guess at the margin in between. That guess is where budgets get wasted, vendors get overpaid, and promising marketing channels get killed too early. The fix is a repeatable formula that converts raw spend into a single, defensible number: cost per signed case. Once you have that number, every budget decision, vendor negotiation, and practice area expansion becomes measurable instead of emotional.

The Core Formula and the Four Rates That Drive It

Cost per signed case answers one deceptively simple question: how much did you spend to acquire one client who actually retained you? The basic formula is total acquisition spend divided by the number of signed cases. But that version hides everything important, because the path from a purchased lead to a signed retainer runs through four conversion stages, and each one leaks money if it underperforms. The better formula multiplies those stage rates together to show you the true funnel behind your cost figure.

Here is how the four rates work in sequence. You purchase a batch of leads. A contact rate tells you what percentage of those leads you actually reached by phone, text, or email. A consult rate tells you what percentage of contacted leads agreed to a consultation. A retention rate tells you what percentage of consultations signed a fee agreement. Multiply the three rates together and you get your lead-to-signed-case conversion. Divide that into your cost per lead and you have cost per signed case.

A worked example makes this concrete. Suppose you buy 100 personal injury leads at $200 each, a $20,000 total spend. Your intake team reaches 60 of those leads (a 60% contact rate). Of the 60, 24 agree to a consultation (a 40% consult rate). Of the 24 consultations, 8 sign (a 33% retention rate). Eight signed cases divided into $20,000 gives you a cost per signed case of $2,500. Now watch what happens when one rate improves. If your intake team lifts the contact rate from 60% to 75%, you reach 75 leads, hold roughly 30 consultations, and sign around 10 cases. Same spend, same leads, but cost per signed case drops to $2,000. That is the power of measuring the funnel rather than just the final number.

This is why buying leads without tracking stage rates is dangerous. A vendor can deliver perfectly qualified leads and still produce a terrible cost per signed case if your intake process drops the ball at the contact or consult stage. Conversely, a mediocre lead source can look acceptable when your intake team is strong. The formula separates lead quality from intake performance, and you need both numbers to make good decisions.

Separating Marketing Cost from Intake Labor Cost

The most common calculation error is leaving intake labor out of the equation. If your paralegal or intake specialist spends four hours a day calling purchased leads, that payroll is part of your acquisition cost, not general overhead. Excluding it produces a flattering number that will not survive contact with your profit and loss statement. The fix is to allocate intake labor to lead acquisition based on time spent on purchased-lead follow-up specifically.

Start by listing every cost that exists because you buy leads. The main categories are:

• Lead purchase cost, including any minimums, exclusivity premiums, or shared-lead discounts
• Intake labor, meaning the portion of staff payroll and benefits tied to calling, texting, and scheduling purchased leads
• Technology costs for CRM seats, dialers, call tracking, and lead management software used on those leads
• Follow-up costs such as text messaging platforms, email tools, and any outsourced answering service
• Attribution costs for tracking, like unique phone numbers or intake scripts tied to specific vendors

For intake labor, use a simple time allocation. If your intake specialist earns $22 per hour fully loaded and spends 50% of a 40-hour week on purchased-lead follow-up, that is $440 per week, or roughly $1,900 per month, added to your acquisition spend. Do this for every person who touches purchased leads. The resulting number is your true monthly acquisition cost.

There is a judgment call on attorney consultation time. Some firms include a portion of attorney hours spent on consultations that came from purchased leads, since those consults are a real cost of acquisition. Others treat consultation time as a cost of doing business that would exist regardless of lead source. Either approach is defensible, but you must pick one and apply it consistently. What you cannot do is include attorney time in some months and exclude it in others, because that makes month-over-month comparisons meaningless. Whichever convention you choose, document it and use it for every calculation.

One more distinction matters: cost per signed case is not the same as cost per lead or cost per consultation. Cost per lead tells you what the vendor charged. Cost per consultation tells you how well your intake converts interest into meetings. Cost per signed case tells you what the whole system costs to produce a client. Track all three, but make budget decisions on the third. If you want to see how a well-run catastrophic injury practice structures its lead-to-client pipeline, the breakdown in how a catastrophic injury attorney leads Houston TX cases shows the same stage-by-stage discipline applied to a high-stakes practice area.

Benchmarking Across Practice Areas Without Overpromising

Cost per signed case varies enormously by practice area, and any benchmark quoted as a single number is almost certainly wrong for your firm. The variation comes from three forces: lead price, case value, and conversion difficulty. A DUI lead might cost $45 while a medical malpractice lead might start at $300, and the malpractice case takes far longer to convert and far longer to pay out. Comparing the two cost figures directly tells you nothing useful.

The right way to benchmark is to compare each practice area against its own history and against its own case economics. A useful framework is to express cost per signed case as a percentage of average case fee. As a rough planning guide, many firms aim to keep acquisition cost somewhere in the range of 10% to 25% of expected fee, with higher percentages acceptable for high-volume, low-complexity matters and lower percentages expected for large-fee cases with long sales cycles. These are planning ranges, not guarantees, and your own data should override any general rule.

Build your benchmarks from the inside out. For each practice area, record monthly lead spend, signed cases, and average fee over at least two full quarters. Then calculate three numbers per area: cost per signed case, cost per signed case as a percentage of average fee, and the trend line over time. A practice area whose cost per signed case is rising while fees stay flat is telling you something is degrading, whether that is lead quality, intake performance, or case mix. A practice area with a stable or falling cost per signed case is a candidate for more budget.

Be cautious about external benchmarks you find online. Published figures often come from firms with different geographies, different intake staffing, and different case mixes. Use them only as sanity checks, never as targets. If a published number is dramatically better than yours, treat it as a prompt to audit your contact and consult rates rather than as proof that you are doing something wrong. The honest benchmark is your own trailing data plus a clear-eyed view of whether each rate in your funnel is improving.

Turning the Number into Monthly Budgets and Vendor Scorecards

A cost per signed case figure is only useful if it changes behavior. The two places it should change behavior most are your monthly lead budget and your vendor scorecard. Both depend on knowing your acceptable acquisition cost, which you derive from case economics. If your average signed case produces a fee that supports an acquisition cost of $2,000, then every vendor and channel must be evaluated against that ceiling.

For monthly budgeting, work backward from signed-case targets. Suppose you want 10 signed personal injury cases next month and your current funnel converts purchased leads to signed cases at 8%. You need roughly 125 leads to hit that target. At $200 per lead, that is a $25,000 lead budget before labor and technology. Add your allocated intake and tooling costs and you have a complete acquisition budget. Compare that total against 10 times your target cost per signed case. If the budget exceeds the ceiling, you have three levers: negotiate lead pricing, improve a funnel rate, or accept a lower case volume. Working backward this way forces the conversation about rates instead of letting spend drift upward.

For vendor scorecards, calculate cost per signed case separately for each lead source. This is the single most valuable use of the formula, because it lets you rank vendors on outcomes rather than on lead price or sales pitch. A scorecard should track, per vendor, for each month:

1. Leads purchased and total spend
2. Contact rate, meaning the percentage of leads reached
3. Consult rate, meaning the percentage of contacted leads who booked a consultation
4. Signed cases and cost per signed case
5. Average fee and cost per signed case as a percentage of fee

Review scorecards monthly and rank vendors by cost per signed case as a percentage of fee. Vendors that consistently land in the best quartile earn more budget and, where volume allows, priority placement. Vendors in the worst quartile get a conversation about lead quality, a reduced allocation, or replacement. This is where a platform like HomeRemodelingLeads illustrates the principle well: it connects contractors with high-intent customer leads across categories like roofing, windows, and remodeling, and the same scorecard logic applies to any pay-per-lead channel, including legal. Judge the source on signed outcomes, not on lead price alone.

For firms buying legal leads at scale, the exclusivity question belongs on the scorecard too. Exclusive leads typically cost more per lead but often convert better because your intake team is not racing three other firms to the phone. Shared leads are cheaper but cap out at limited distributions, and the discount is only worth it if the resulting cost per signed case stays below your ceiling. Run the calculation both ways before committing volume. A platform built around verified, exclusive, practice-specific leads, like the ones available through AttorneyLeads.com, gives you cleaner inputs for this math because each lead has exactly one firm competing for it.

One final habit separates firms that use this number well from firms that just calculate it once. Recalculate cost per signed case monthly, and keep the historical series visible. The number will move, and the movement is the signal. A rising cost per signed case with stable lead prices points to intake decay. A falling cost per signed case after an intake script change validates the change. A vendor whose cost per signed case improves for three straight months has earned a larger allocation. The formula is not a report you file away; it is the steering wheel for your acquisition spend.

Start with one practice area and one month of clean data. Pull your lead invoices, allocate your intake labor honestly, count signed cases, and run the division. The first number will probably be worse than you hoped, and that is fine, because it is real. From there, improve one rate at a time, recheck the math monthly, and let the cost per signed case, not the lead price, decide where your next dollar goes.