How to Measure ROI on Law Firm Marketing Spend: Case Value, CAC, and a Worked Example

Your agency’s monthly report shows clicks, impressions, and calls, and the lines on its charts may even trend up. You still can’t say whether last month’s spend paid for itself.

If you’ve ever closed that report and wondered which of those calls turned into a client, you’re not alone. Here’s the problem: none of those numbers is a return.

Below, I’ll show you how to measure ROI on law firm marketing spend using two numbers: case value and client acquisition cost. You’ll get each one by fee type, channel, and practice area, plus a worked example.

What Is Marketing ROI for a Law Firm?

Marketing ROI (return on investment) is the fees your marketing brought in, minus what the marketing cost, divided by that cost. It tells you how many dollars came back for every dollar you spent.

Clio’s guide to marketing ROI for law firms uses the same formula: revenue from marketing minus marketing costs, divided by marketing costs. In its example, a $2,000 campaign that brings in $10,000 returns 400%, or $4 back for every $1 spent after covering the cost.

The formula is simple. The hard part is filling in the two numbers honestly.

“Revenue from marketing” should mean fees your firm collected from clients who came in through marketing. Leads, calls, and gross settlements don’t count.

“Marketing costs” should mean everything you paid to get those clients. That includes ad spend, agency fees, software, and referral fees, which many firms leave out.

Once both numbers are right, law firm marketing ROI stops being a guess and becomes a figure you can compare month to month and channel to channel.

How to Calculate Your Average Case Value

Case value is the average net fee your firm keeps from one signed case of a given type. It’s the top half of every ROI calculation, so it’s worth getting right before you look at a single ad report.

Start with fees collected, not fees billed or quoted. Then subtract what didn’t stay with the firm: referral or co-counsel fees, refunds, write-offs, and case costs you advanced and never recovered.

Pull the last 12 to 24 months of closed cases from your case management system and sort them by practice area. If you use Clio or a similar tool, a report of collected fees by practice area and open date gets you most of the way.

Use the median instead of the average when a few large cases skew the number. One seven-figure verdict can make a practice area look far more valuable than the typical case it signs.

How you calculate case value depends on how you bill, and contingency, flat fee, and hourly work each need their own approach.

Contingency Fee Cases

For contingency fee cases, multiply your average recovery by your fee percentage, then by the share of signed cases that actually pay. That last step is the one many firms skip.

Cases that close with no recovery still count. They cost you intake time, case costs, and attorney hours, so they belong in the math at zero.

Here’s a hypothetical. Say your average recovery is $30,000, your fee is one third, and 80% of signed cases pay. Your case value is $30,000 × 1/3 × 0.80, or about $8,000 per signed case.

Flat Fee Cases

For flat fee work, case value is the fee you collect times the average number of paid jobs each new client brings. For a lot of estate planning and immigration firms, that’s close to one fee per client.

Refunds come off the top: a $3,000 package with a 10% refund rate is worth $2,700 to you.

Repeat work is where flat fee practices earn more than the first invoice suggests. An estate planning client may come back for updates after a marriage, a move, or a new grandchild, and may send family members.

Track repeat and referred work separately from the first fee. It’s real value, but it arrives later and shouldn’t be credited to this month’s ads.

Hourly Cases

For hourly cases, case value is the hours billed and collected on a typical case, times your rate. Collected is the word doing the work in that sentence.

Unpaid invoices aren’t a return, and neither are retainer deposits sitting in trust until you’ve earned them.

Hourly practices often need more than one case value. In family law, a contested custody case and an uncontested divorce sit in the same practice area but can bring in very different fees.

If your marketing tends to attract one type more than the other, a single family law case value will mislead you. Split it into two or three case types that match how leads come in.

How to Calculate Client Acquisition Cost

Client acquisition cost (CAC) is your total marketing cost for a period divided by the number of new clients who signed in that period. It’s the bottom half of the ROI picture.

Include every cost tied to getting a client: ad spend, agency and freelancer fees, website costs, call tracking, and intake software. If you hired an intake person because of marketing volume, add their time too.

Leave out costs that would exist without marketing. Your case management software and your general office staff belong in overhead, not CAC.

Here’s a simple version. If your firm spent $15,000 on marketing last quarter and signed 30 new clients, your CAC was $500.

You’ll also see this called cost per signed case. It’s the same number, and it’s the one we use with clients because it keeps everyone focused on cases, not leads.

The blended number is a starting point, not an answer. A firm-wide CAC of $500 can hide one channel at $250 and another at $1,500.

The Takeaway: CAC is your cost per signed case, and it only becomes useful once you split it by channel and by practice area.

Measure Client Acquisition Cost by Marketing Channel

To measure CAC by channel, divide each channel’s total cost by the signed cases that channel produced. That tells you which channels are paying for themselves and which are riding along.

Many accounts we audit count every form fill or call as a conversion, whether or not it became a client. The dashboard looks healthy, and nobody can say what a signed case costs.

Review channel CAC monthly, but make budget decisions quarterly. A single month is too few cases to judge most channels fairly.

Google Ads and Local Services Ads

Paid search is the easiest channel to measure, as long as signed cases flow back into Google Ads.

Google’s offline conversion import lets you “measure what happens in the offline world after your ad results in a click or call to your business.” Save the GCLID (Google Click ID) with each lead in your CRM, then send the signed case back to Google Ads as a conversion.

Local Services Ads (the Google Screened listings that charge per lead instead of per click) need the same discipline. Mark which LSA leads became clients, so you’re dividing LSA spend by signed cases, not by leads. Once your law firm PPC account knows which clicks became clients, you can judge campaigns by cost per signed case instead of cost per lead.

SEO and Content

SEO cost is your monthly SEO retainer plus content and website work, and its return is the signed cases that came from organic search. The cost is easy to total, and the cases take a little more work to find.

Use call tracking on your website so organic visitors see a dedicated number, and tag web forms with the landing page. Then ask every new client “How did you hear about us?” and check it against what tracking recorded.

Judge law firm SEO over several months, not one. Rankings take time to build, and early months carry the cost before the cases arrive.

Referrals, Reviews, and Email

Referral fees paid to other attorneys, where ABA Model Rule 1.5(e) and your state allow them, are a marketing cost, and they belong in your CAC.

A referral fee is what you paid to get a case, so it’s an acquisition expense. Put it in the same report as Google Ads and SEO.

Email to past clients and review requests usually cost very little. They often bring in repeat and referred work, which shows up as a low CAC when you track it.

Add a “referred by” field to your CRM at intake, and fill it in on every new client. Without it, referral cases get credited to whatever channel the client touched last.

Measure Client Acquisition Cost by Practice Area

Split your CAC by practice area, because personal injury, family law, and estate planning each have their own case value and lead costs. A firm-wide number blends a $2,000 estate plan with an $8,000 injury case and tells you nothing about either.

Lead costs alone vary widely. LocaliQ’s legal search benchmarks are based on US campaigns from April 2022 to March 2023. They put the median cost per lead at $159.17 for personal injury, $103.54 for family law, $101.49 for criminal law, and $72.24 for estate and probate.

Those are medians for leads, not signed cases. Your sign rate turns them into a CAC, and sign rates vary by practice area too.

A higher CAC is fine when case value is far higher. A personal injury firm can afford a much higher cost per signed case than an estate planning practice, because each case is worth more.

The useful comparison is the ratio inside each practice area. Divide case value by CAC for each one, and you’ll see where an extra dollar of marketing does the most work.

A Worked ROI Example: Family Law and Estate Planning

Here’s a hypothetical firm that spends $12,000 a month on marketing across family law and estate planning. The numbers are illustrations, not client results, but the math is the same one you’d run on your own data.

Together, the firm spent $12,000 and brought in $92,000 in fees. The blended ROI is about 667%, which looks great and tells the owner very little.

Split by practice area, the picture is clearer. Both practices pay for themselves, but each family law dollar returns about twice what an estate planning dollar does.

Notice that estate planning has the lower CAC and still the lower ROI. Cheap clients aren’t automatically good clients if each one brings in less.

That doesn’t mean cutting estate planning. Those clients tend to return and refer, and that later value isn’t in this month’s math.

The Takeaway: A blended ROI hides which practice to grow. Run the numbers by practice area before you move a dollar.

Measure Contingency Fee ROI by the Month a Case Was Signed

Measure ROI by grouping signed cases by the month they were signed, not the month the fee arrived. Marketers call this a cohort, and it’s the fairest way to judge a channel whose cases pay late.

Contingency cases make this obvious. A personal injury case signed in January may not pay until the following year or later, long after the ads that brought it in.

If you calculate ROI by calendar month, January looks like a loss. The spend landed in January, and the fees show up in a different year’s report.

Firms that read their numbers this way often cut a channel that’s working, right before its cases start paying.

Here’s the fix. Credit each signed case with its expected case value on the day it signs, using the contingency math from earlier. Then replace the estimate with the actual collected fee when the case closes.

This lets you judge a channel within a quarter, using expected value, while your books stay honest over time. Each cohort keeps updating as its cases resolve.

A simple spreadsheet works: one row per signed case, with columns for sign date, source, practice area, expected value, and collected fee. Filter by sign month and source, and you have ROI by cohort.

How to Track Every Signed Case Back to Its Source

Use call tracking and a CRM to tag every lead with its source at first contact, then keep that tag through intake to the signed agreement. If the tag drops off at intake, your law firm marketing ROI report falls apart.

Use call tracking with a separate number for each channel: Google Ads, LSAs, organic search, Google Business Profile, and offline ads. Add hidden fields to your web forms that capture the landing page, the source, and the GCLID.

Send all of it into one CRM, and make the source a required field before a lead can be marked signed. In our experience, that one rule fixes more ROI reports than any dashboard.

Intake is where tracking often breaks. In Clio’s 2024 secret shopper test, 48% of firms neither answered the phone nor called back.

A lead that never gets a call can’t become a case, so good marketing looks bad and the report blames the channel instead of the phone.

Maybe you’ve tried to trace last month’s best case to a channel and come up empty. The usual culprit is a tracking gap.

Good reporting should put spend, leads, and signed cases for each channel on one page. Whatever tool you use, that’s the view you need.

What Is a Good Marketing ROI for a Law Firm?

A good law firm marketing ROI is any channel where case value comfortably exceeds CAC, with room to add spend. There’s no single target ratio that fits every practice area.

You’ll see ratios like 5:1 quoted online, sometimes from agency whitepapers. We’d rather you compare each channel to its own trend and to your other channels than chase a number someone else picked.

The better test is what happens when you scale. If CAC holds steady as you add budget, the channel has room to grow. If it climbs quickly, you’re near the ceiling.

Marketing ROI on fees isn’t profit. Attorney time, staff, rent, and software still come out of every fee, so a channel at 150% may barely cover its share of overhead.

For most firms, the goal is the most signed cases at a cost per signed case you can sustain.

Final Thoughts: Measure ROI in Signed Cases

Law firm marketing ROI comes down to two numbers: what a signed case is worth and what it costs to get one. Measure both for each channel and practice area, and judge late-paying cases by the month they signed.

Once you have that, budget decisions get easier, because you’ll know where the next dollar should go and which channel to cut.

Do you know what your last signed case cost you? I’m a former Googler who ran an SEO division in Sydney from 2010 to 2013. Neon Ambition has 12+ years in digital marketing and helps law firms tie their marketing spend to signed cases.

Call Neon Ambition at 512-865-8050 or request a free marketing audit. We’ll review your tracking with you and show you what each channel is returning in signed cases and collected fees.

Frequently Asked Questions

How Do You Calculate Marketing ROI for a Law Firm?

Subtract your marketing cost from the fees that marketing brought in, then divide by the cost. Run it for each channel and practice area. Use collected fees, and count referral fees as a cost.

How Long Does It Take to See ROI From Law Firm Marketing?

Paid search and Local Services Ads can bring in signed cases within weeks, and SEO usually takes several months. Contingency fees can take a year or more to collect, so track those by sign month. Our guide to how much a law firm should spend on marketing covers budgeting for that gap.

Should Referral Fees Count as a Marketing Cost?

Yes. It’s what you paid to get the case, just like ad spend. Leaving it out makes referral cases look free and makes every other channel look worse by comparison.