What LTGP to CAC Ratio Do Trade Contractors Need? Why the 3:1 Rule Is Wrong and How to Calculate the Right Target
MOZI 6 Framework — The theory of constraints says there is exactly one bottleneck limiting your business right now. This series helps you find it, fix it, and find the next one.
Find your constraint →Built on Alex Hormozi's constraint-first framework — adapted for trade contractors.
The LTGP:CAC ratio is M7 — the metric that synthesizes everything upstream and answers the only question that matters about your growth engine: is it working? M4 (LTGP) and M6 (CAC by channel) are the inputs. M7 is the verdict. For a trade contractor with 3 human touchpoints in delivery, the target is 12:1 — not the 3:1 benchmark that circulates in business content, which is a SaaS metric that doesn't apply to labor-delivered services. Marcus Rivera's BOMA channel was running at 38:1. His Google Ads were at 1.1:1. Two channels, the same business, 35x difference in financial efficiency. This post is for HVAC, plumbing, electrical, roofing, and general contracting owners who want to understand what ratio they need, how to calculate it by channel, and what to do when a channel is above or below target.
We calculate M7 by channel in session one — then use it to rank every acquisition investment the business is making. It's the clearest picture of whether the growth engine is working or burning money.
Book a Clarity CallM7 is where the metrics section of MOZI comes together. Everything calculated upstream — LTGP from M4, CAC by channel from M6 — flows into a single ratio that tells you whether your acquisition model is financially sound or quietly destroying value.
The formula: LTGP:CAC Ratio = Lifetime Gross Profit per Customer ÷ Customer Acquisition Cost
A 12:1 ratio means every dollar you spend acquiring a client returns $12 in lifetime gross profit. A 1:1 ratio means you are breaking even on acquisition — with nothing left over for overhead, owner pay, or growth.
What LTGP to CAC Ratio Do Trade Contractors Need?
The required ratio depends on how many human touchpoints are in your delivery process. Every human who touches a client relationship adds cost that must be recovered from the margin between LTGP and CAC. The human-adjusted targets:
Rivera HVAC has three humans in delivery: Marcus (owner, commercial relationships), Sandra (admin, scheduling, quoting), and Jorge (lead technician, field delivery). That makes it a 3-human operation — target ratio is 12:1.
Why Is the 3:1 LTV to CAC Rule Wrong for Trade Contractors?
The 3:1 benchmark originated in SaaS. In a software business, once the product is built, the marginal cost of serving one more customer approaches zero — the server costs a few more cents, nothing else changes. A 3:1 LTV:CAC ratio leaves meaningful margin after acquisition because delivery is nearly free.
For a trade contractor, delivery costs are the dominant expense in the business. Field labor, materials, scheduling, and quality control consume 20–45% of revenue before overhead is even considered. A 3:1 ratio against LTGP (which already reflects gross margin) means the business has almost nothing left after acquisition and overhead costs are stacked on top of each other.
Put concretely: if Marcus acquired a commercial client with an LTGP of $53,352 and his CAC was $17,784 (a 3:1 ratio), that $17,784 acquisition cost would consume over 33% of the lifetime gross profit before a single dollar of overhead was paid. At 12:1 — CAC of $4,446 — acquisition consumes 8.3% of LTGP and leaves the remaining 91.7% to cover overhead, pay the team, pay the owner, and fund growth.
How Do I Calculate My LTGP to CAC Ratio as a Contractor?
Step 1: Calculate LTGP for each client type (from M4).
Step 2: Calculate CAC for each acquisition channel (from M6).
Step 3: Divide LTGP by CAC — separately for each channel.
Here's Marcus's full M7 scoreboard after doing the work:
| Channel | Client LTGP | CAC | Ratio | vs. Target |
|---|---|---|---|---|
| BOMA Network | $53,352 | $1,400 | 38:1 | 3× above target — invest more |
| LinkedIn Outreach | $53,352 | $1,425 | 37:1 | 3× above target — scale up |
| Passive Referrals | $53,352 | ~$0 | ∞:1 | Build an active program |
| Google Ads | $3,306 | $2,900 | 1.1:1 | Far below target — cut |
The Google Ads line is the most important number in this table. The LTGP is $3,306 — not because Google Ads is an expensive channel, but because the clients it produces are residential homeowners with low lifetime value. CAC of $2,900 against LTGP of $3,306 is a 1.1:1 ratio. That's not a marketing problem. That's a client-type mismatch problem — the channel is optimized for the wrong avatar entirely.
The M7 scoreboard is what we build in session one — then use to make every marketing allocation decision for the next 12 months with the actual ratios visible.
Book a Clarity CallWhat Does a Very High LTGP to CAC Ratio Mean for a Contractor?
A ratio significantly above target — 38:1 against a 12:1 target — is not just a good sign. It's an opportunity signal that most contractors miss.
If the target is 12:1, and the maximum healthy CAC is LTGP ÷ 12, Marcus's ceiling on BOMA spend is:
Marcus has $3,046 per commercial client acquired that he could spend on BOMA-related acquisition activities before his ratio touches the floor. With 9 clients acquired last year from BOMA, that's $27,414 of unused acquisition capacity — enough to fund a part-time business development person focused entirely on commercial property manager relationships.
The instinct to minimize CAC is wrong when the ratio is far above target. The goal is not to spend as little as possible on acquisition. The goal is to acquire as many of the right clients as possible while staying above 12:1.
What Should a Contractor Do If Their LTGP to CAC Ratio Is Below 12:1?
Below 12:1 means acquisition is consuming too much of lifetime gross profit. Before choosing a fix, identify which variable is most out of line:
Marcus's Google Ads fix was simple once the ratio was visible: the channel was producing the wrong client type at high cost. Fixing the channel's targeting to reach commercial property managers would have taken months of trial and error. Cutting it and doubling BOMA spend took one decision.
"My BOMA ratio was 38:1 and I thought I was being smart by keeping costs low. My CFO pointed out I had $27,000 of unused acquisition budget hiding in that channel — money I could spend on business development and still be above the healthy 12:1. I was leaving growth on the table to save $4,000 a year."
Frequently Asked Questions About LTGP:CAC Ratio for Trade Contractors
What LTGP to CAC ratio do trade contractors need?
The required LTGP:CAC ratio for a trade contractor depends on how many human touchpoints are involved in delivering the service. The human-adjusted targets are: 0 humans (SaaS/digital) = 3:1, 1 human (solo operator) = 6:1, 2 humans (e.g., owner + one delivery person) = 9:1, 3 humans (e.g., owner + salesperson + technician) = 12:1. Most trade contractors with a full service operation — owner, admin, and field — are 3-human businesses requiring a 12:1 ratio. The 3:1 rule that circulates in business content is a SaaS benchmark and is inappropriate for any business where human labor is the primary delivery mechanism.
How do I calculate my LTGP to CAC ratio as a contractor?
LTGP:CAC ratio = Lifetime Gross Profit per Customer ÷ Customer Acquisition Cost. Calculate LTGP first: Annual Revenue per Client × Gross Margin % × Average Client Lifespan. Then calculate CAC by channel: total channel spend including owner time ÷ clients acquired from that channel. Divide LTGP by CAC to get the ratio. Do this separately for each acquisition channel — Google Ads, referrals, networking, LinkedIn — because the ratio will vary dramatically by channel and each channel requires a separate decision. A ratio below your target signals either LTGP is too low, CAC is too high, or the channel is producing the wrong client type.
Why is the 3:1 LTV to CAC rule wrong for trade contractors?
The 3:1 LTV:CAC benchmark originated in SaaS (Software as a Service) businesses, where the marginal cost of serving an additional customer approaches zero after the software is built. In a SaaS company, a 3:1 ratio leaves meaningful profit after acquisition costs. For a trade contractor, every client requires human labor to deliver — which represents a significant ongoing cost built into gross margin. A 3:1 ratio for a trade contractor with 3 human touchpoints means there is almost no margin left after delivery costs and acquisition costs are accounted for together. The human-adjusted target of 12:1 accounts for the real economics of labor-delivered services.
What does a very high LTGP to CAC ratio mean for a contractor?
A ratio significantly above your target — say 38:1 against a 12:1 target — is positive but also signals an underinvestment opportunity. If your max healthy CAC is LTGP ÷ 12, and you are acquiring clients at a fraction of that ceiling, you have unused budget for acquisition investment. A contractor with a 38:1 ratio could triple their acquisition spend on that channel and still be well above the healthy 12:1 target — meaning they could add a business development person, attend more industry events, or run targeted outreach campaigns without degrading their financial model. The goal is not to minimize CAC. It is to maximize client acquisition while staying above the ratio target.
What should a contractor do if their LTGP to CAC ratio is below 12:1?
A ratio below 12:1 for a 3-human contractor means the business is acquiring clients at too high a cost relative to what they are worth. There are three possible fixes, in order of preference: (1) Increase LTGP — raise prices, improve gross margin, improve retention rate, or shift the client mix toward higher-LTGP accounts. (2) Decrease CAC — find lower-cost acquisition channels, improve conversion rate so fewer contacts are required per client acquired, or reduce agency fees and ad spend on inefficient channels. (3) Stop acquiring from that specific channel entirely and reallocate the budget to channels with better ratios. Improving the ratio requires identifying which variable is most out of line — LTGP or CAC — before choosing a fix.
Where Does M7 Connect in the MOZI Framework?
M7 is the final metric in the METRICS section of MOZI — the synthesis of everything from M0 through M6. A healthy M7 across all channels means the growth engine is working. An unhealthy M7 on any channel means there's a specific upstream problem to fix, traceable back to LTGP (M4), CAC (M6), retention (M5), or gross margin (M3). The full metrics series is on the blog. The next section — MODEL — addresses what happens when the metrics look right but the business model itself has structural constraints: wrong pricing architecture, revenue that doesn't grow faster than costs, or growth that makes the owner's life worse rather than better. And as always, how acquisition spend is structured and documented has direct tax implications — something our tax strategy practice addresses alongside the Fractional CFO work.
Know Your Ratio by Channel Before Your Next Marketing Dollar.
One number — LTGP:CAC — tells you whether each acquisition channel is working or destroying value. Most contractors have never calculated it. The ones who have almost always find $20,000+ of misdirected spend to reallocate.
Marcus's Google Ads: 1.1:1. His BOMA network: 38:1. Same budget. 35× difference in financial efficiency. One number made the decision obvious.
