Law Firm Marketing ROI: How to Calculate It

Your marketing report shows leads, clicks and cost per lead, but not which dollars became signed cases. Law firm marketing ROI (return on investment) answers that: the fees your marketing brought in, minus what it cost, divided by what it cost.

For a criminal defense or family firm, the number that should decide where your marketing spend goes is cost per signed case by channel, set against the fee for that case type. Below: a labeled worked example, the counting rules from our own cost-per-case reports, and how to send signed cases back to Google.

Many firms can’t track marketing this way yet. In a Best Law Firms survey published in November 2025, only 37% of firms said they have the systems and technology in place to track the return on their marketing dollars.

Key Takeaways

• ROI subtracts what the marketing cost; return on ad spend (ROAS) does not. A 4x ROAS is a 300% ROI.
• Judge cost per signed case against the average fee for that case type, not against cost per lead.
• In our hypothetical, the channel with $25 leads pays $1,500 per signed case.
• Google’s offline conversion import ties each signed case, and its fee, to the ad click that started it.

On this page: The three formulas · Worked example · Case value · Counting rules · Client journey · Offline conversions · FAQ · Sources

ROI, ROAS and cost per signed case answer different questions

ROI tells you whether marketing paid for itself. ROAS shows the fee dollars each ad dollar brought in, and cost per signed case shows what one new client cost.

Clio writes the ROI formula as (revenue from marketing minus marketing costs) divided by marketing costs. Google defines a target ROAS as “the average conversion value (for example, revenue) you’d like to get for each dollar you spend on ads”. ROAS subtracts nothing.

Mixing up the first two inflates the result. Four dollars in fees for every ad dollar is a 4x ROAS, but subtract the dollar you spent, and the ROI is 300%, not 400%.

For the other funnel numbers, from lead to consult rate to collected fees, see our law firm dashboard post.

A worked example shows the cheapest leads can cost the most per case

Hypothetical: the firm and every number in this section are made up to show the math. They are not client results or benchmarks.

A criminal defense firm spends $12,000 on ads in one month across Google Search ads, Google Local Services Ads (LSA) and Meta’s social media ads on Facebook and Instagram. Each signed case carries an agreed flat fee.

Meta brings the cheapest leads and the most expensive cases. LSA signs cases for the least, $600 each, but its fees run smaller, so Google Search returns the most per ad dollar. Ranked by cost per lead, these channels come out in the exact reverse of their ROAS order.

Ads were not the only cost. Say the agency fee plus call tracking and customer relationship management (CRM) software add $4,000, for $16,000 in all:

• ROI on agreed fees: ($48,000 minus $16,000) divided by $16,000 = 200%.
• ROI on cash collected: if $36,000 of the $48,000 has been paid so far, ($36,000 minus $16,000) divided by $16,000 = 125%.

Track both: agreed fees show what the marketing sold, and collected cash shows what reached the bank. For channel setup, see our guides to Google LSA for attorneys and Meta ads for law firms.

Every lead source belongs in the table, including SEO, content marketing and referrals, each with its monthly cost. Cases with no ad click land in those rows. Best Lawyers suggests recording at intake “where each client first encountered your practice” to split them; when that answer and the click data disagree, go with the click.

Case value sets the most a signed case can cost

The most you can pay for a signed case is the average fee for that case type divided by the ROAS you need. If you need at least 3x on a $3,000 average fee, a signed case can cost up to $1,000.

In the hypothetical, Meta’s cases cost $1,500 on a $3,000 average fee, a 2x return and below that line. Google’s cost $750 on a $3,750 average fee, a 5x return.

Channels bring different case mixes, so one firm-wide average fee hides gaps like that. Set the fee, and the most you will pay, for each case type.

How we set case value in our cost-per-signed-case reports, as of October 2026:

• We take the agreed fee recorded on the matter when it shows one clear amount.
• When it shows several amounts or none, we use an average for that practice area and label it an estimate.
• We report cash received apart from the amount billed, because a bill can go out at the full fee while only a deposit has been paid.

Signed-case tracking needs written counting rules

Two people can count the same month and get two different costs per case. These are the written rules in ROI Society’s cost-per-signed-case reports as of October 2026:

1. A signed case is a matter opened in the firm’s case management system that month. A booked consult does not count. Two matters for one client count as two cases.
2. Matters with no money on them are left out, and listed. A matter counts when it has a fee, a bill or a payment. The report lists each one it skipped, so a real case nobody has billed yet gets added back.
3. Credit comes from the CRM and the click, not a hand-typed source. We read the platform field and tags on the lead in the firm’s CRM, then click data such as the Google click ID or UTM tags.
4. A chat widget is not a channel. A website chat tool or instant auto-reply only answers the lead; credit goes to the ad or search behind it.
5. Doubtful credit gets a cautious figure. When a case’s channel rests on a weak signal, the report shows cost per case with and without those cases.
6. Counties are judged on a rolling 90 days. The report also shows every channel over the same 90 days.

For intake and lead follow-up, see our lead management guide. If you can’t fill in the channel table for last month, a Growth Evaluation reviews your marketing, intake and budget to show what is working and what is leaking.

The client journey shows where each channel leaks

Count each step from search to signed fee by channel, and the step where a channel falls off tells you what to fix.

Hypothetical: after a Friday night DWI arrest, someone searches “DWI lawyer near me” on Saturday, clicks your ad and calls. Intake books a Monday consult, and they sign and pay a deposit.

Each step is a count: clicks, calls and forms, consults booked and held, signed cases, and agreed and collected fees. In the worked example, Google’s lead-to-case conversion rate was 1 in 5 (8 of 40), while Meta’s was 1 in 60 (2 of 120).

If Meta’s leads booked consults at Google’s rate but rarely signed, look at the consult and the fee. If they rarely booked at all, the ad is reaching the wrong people, or intake is too slow to reach them.

Clio flags two traps here: ignoring multi-touch attribution, when a client meets you through several channels before hiring, and failing to separate branded searches (your firm’s name) from non-branded ones. A person who saw your Meta ad and then searched your name lands in Google’s column, so report branded search on its own line.

Sending signed cases back to Google teaches bidding what a case is worth

Your CRM knows which leads signed; Google Ads does not until you tell it. 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.”

The setup has four steps:

1. Save the click ID with the lead. Google gives each ad click a Google Click ID (GCLID). Its setup guide says you can “store each GCLID with the corresponding prospect’s information”.
2. Send the case back when it signs, with the GCLID, the signing date and the fee as the conversion value.
3. Add enhanced conversions for leads. Google calls it “an upgraded version of offline conversion import that uses user-provided data”, such as a hashed email or phone number.
4. Send an earlier step too, such as consult held. Google’s FAQ allows a GCLID upload “so long as it’s no longer than 90 days” after the click, or 63 days for enhanced conversions. A case that signs later can’t be credited to its click.

Send the fee with each case. Google says target ROAS “predicts future conversions and associated values using your reported conversion values”. Its conversion values page says to use different values “if each of your sales or leads has a different conversion value.” Send a felony and a first DWI at their own fees, and the bidding can tell them apart. We send signed cases back to Google on the accounts that are fully connected; our post on AI PPC management shows how we run it.

Meta offers the same loop. Its Conversions API for CRM sends “down-funnel event data from your CRM back to Meta.”

Frequently asked questions about law firm marketing ROI

What is a good marketing ROI for a law firm?

Clio says there’s no one-size-fits-all number, though some legal marketers call a 5:1 revenue-to-cost ratio good and 10:1 outstanding. Our take: set your own floor. Divide the average fee for each case type by the ROAS you need, and treat the result as the most a signed case can cost.

What is the 80/20 rule for lawyers?

The 80/20 rule is the idea that a small share of causes produces most of the results. For marketing ROI, use it as a check: sort your campaigns by signed fees and see whether a few carry most of them. Your own numbers set the split.

How long before a channel’s ROI is fair to judge?

Clio notes that paid ads can show results in weeks, while SEO and content marketing may take several months. Our take: give SEO a longer window than ads before you cut it.

Start with last month’s signed cases by channel

Pull last month’s ad spend, signed cases and agreed fees for each channel, and lay them out like the worked example’s table. Cost per signed case, ROAS and ROI side by side is where data-driven marketing for a law firm starts.

Recheck it each quarter with our quarterly marketing audit. If Google Search is your biggest line, read our guide to Google Ads for criminal defense lawyers; our Google Ads management includes conversion tracking setup.

Sources

1. Best Law Firms, “Law Firms Avoiding Marketing Cuts, But ROI Remains a Problem,” https://www.bestlawfirms.com/articles/law-firms-avoiding-marketing-cuts-but-roi-remains-a-problem/7139, checked October 21, 2026.
2. Clio, “Marketing ROI for Lawyers: Measure, Track and Improve Law Firm Marketing Performance,” https://www.clio.com/blog/marketing-roi-for-law-firms/, checked October 21, 2026.
3. Best Lawyers, “Law Firm Marketing ROI: Strategies for Small and Midsize Firms,” https://www.bestlawyers.com/article/law-firm-marketing-roi-strategies/6720, checked October 21, 2026.
4. Google Ads Help, “About Target ROAS bidding,” https://support.google.com/google-ads/answer/6268637, checked October 21, 2026.
5. Google Ads Help, “About offline conversion imports,” https://support.google.com/google-ads/answer/2998031, checked October 21, 2026.
6. Google Ads Help, “Set up offline conversions using Google Click ID (GCLID),” https://support.google.com/google-ads/answer/7012522, checked October 21, 2026.
7. Google Ads Help, “About enhanced conversions for leads,” https://support.google.com/google-ads/answer/15713840, checked October 21, 2026.
8. Google Ads Help, “Offline conversion imports FAQs,” https://support.google.com/google-ads/answer/10029210, checked October 21, 2026.
9. Google Ads Help, “About conversion values,” https://support.google.com/google-ads/answer/13064207, checked October 21, 2026.
10. Meta for Developers, “Conversions API for CRM integration,” https://developers.facebook.com/documentation/ads-commerce/conversions-api/conversion-leads-integration, checked October 21, 2026.

Header image: AI-generated image.