# What Is a Healthy Gross Margin for Plumbers? Key Benchmarks
A healthy gross margin for a plumbing business falls between 35% and 50%, with top-performing shops consistently hitting 45–55% on residential service work. Most small to mid-sized plumbing companies land somewhere in the 30–40% range. Anything below 30% is a warning sign that labor costs, materials markup, or job pricing are quietly eroding the business's ability to survive a slow season.
This article is for informational purposes only and doesn't constitute financial or accounting advice. Talk to a CPA who actually understands trade businesses before you change your pricing or cost structure — the general advice below won't account for your state's workers' comp rates or your specific supplier terms.
Gross margin measures one thing: what's left after you pay for the labor and materials that went directly into a job.
Gross margin = (Revenue − Cost of Goods Sold) ÷ Revenue × 100
For a plumbing company, COGS includes direct field labor (wages plus burden — payroll taxes, workers' comp, benefits), materials and parts used on the job, equipment rental tied to a specific project, and subcontractor costs. It does not include office salaries, truck lease payments, software subscriptions, or marketing. Those sit below the gross profit line as operating expenses and affect net margin instead.
Here's a worked example. Say your company billed $680,000 last year. Direct labor (field techs only) ran $210,000, materials cost $125,000, so COGS totals $335,000.
Gross Profit = $680,000 − $335,000 = $345,000
Gross Margin = $345,000 ÷ $680,000 = 50.7%
That's a strong number — but watch how little it takes to break it. If that same company under-billed materials by just 15% (a common error when techs grab supplies off the truck without logging them), materials cost balloons to roughly $144,000 and gross margin drops to about 48%. Two points doesn't sound dramatic until you multiply that slippage across hundreds of service calls in a year — that's easily $20,000 or more quietly walking out the door, and most owners never trace it back to the truck stock.
Industry benchmarking sources — trade associations like PHCC and contractor-focused financial consultants — generally place median gross margin for small plumbing operations (under $2M in revenue) in the 30–40% range. Mid-sized companies ($2M–$10M) that have invested in flat-rate pricing and dispatch software tend to cluster closer to 38–48%.
| Business type | Typical gross margin | Why |
|---|---|---|
| Solo/owner-operator | 45–60% | Owner IS the labor — no burden to layer on |
| Small residential service (2–5 techs) | 32–42% | Labor burden and callback risk start eating in |
| Mid-sized residential/light commercial | 38–50% | Flat-rate pricing helps; overhead stays below the line |
| Commercial new construction | 18–28% | Competitive bidding compresses everything |
| High-end remodel/specialty | 45–60% | Less price sensitivity, complexity commands a premium |
The commercial new construction number trips up a lot of owners who assume bigger contracts mean bigger margins. They don't. General contractors bid hard, payment timelines stretch out for months, and material waste on large jobs is nearly impossible to control without a dedicated project manager watching the numbers daily.
Labor burden is usually underestimated. Most owners know their techs' hourly rate. Fewer have worked out the fully-loaded cost — payroll taxes (~7.65% FICA), workers' comp (15–25% of wages in the trades, depending on state and claims history), health insurance, PTO. A tech earning $28/hour might genuinely cost $38–42/hour all-in. If your pricing is calibrated to $28, you're pricing off a number that was never true.
Materials markup is often too timid. Standard practice in residential service is to mark up materials 25–50% over actual cost. Plenty of small shops mark up 10–15% "to stay competitive" and leave real money on the table — a homeowner with water on the floor is not price-shopping a $45 shutoff valve. Shops that move to flat-rate pricing books tend to see a noticeable jump in gross margin, often in the high single digits to low double digits, simply because the pricing is no longer anchored to cost-plus guesswork.
Callbacks are a silent tax. One callback — a tech driving back out to fix a leak missed on the first visit — can consume the entire gross profit on that job and then some. A callback rate above 3–5% of completed jobs is a margin problem that never shows up as its own line item on a P&L; it just shows up as "margin's a little soft this quarter" with no obvious cause.
Billable efficiency compounds quietly. A full-time tech works roughly 2,080 hours a year. After drive time, shop time, training, and admin work, most techs bill 65–75% of that. Well-run shops push 78–82% through tight routing and pre-stocked trucks. Each point of billable efficiency recovered on a $38/hour tech is worth something in the neighborhood of $790 a year per tech — not much on one truck, but real money across a five-truck fleet.
Residential service is the higher-margin business, and it's not close. Homeowners decide fast, they're less price-sensitive than a general contractor comparing three bids, and jobs are small enough that one pricing mistake doesn't sink your quarter. Target 40–50% gross margin here; drain cleaning, water heater swaps, and fixture installs done at scale with flat-rate pricing can push past 45%.
Commercial work runs on different rules. Design-build protects margin better than hard-bid work, but even then 28–38% is realistic, and hard-bid new construction under $5M rarely clears 25% gross for a smaller contractor.
The practical takeaway: if you do both, track margin by job type, not in aggregate. A company doing $3M at a blended 32% might actually be running residential at 46% and commercial new construction at 18% — meaning the residential side is quietly subsidizing the commercial side, and nobody's decided that on purpose.
Raising prices is the fastest lever, but it's not the only one.
Underbidding service calls to win the job is the most common one, and it's usually unnecessary — a homeowner with an active leak is not choosing you over a competitor because of a $50 difference. Competing on price when you don't have to trains your own techs to apologize for your rates.
Forgetting to re-price after supplier increases is close behind. Materials costs in the plumbing supply chain jumped hard in 2021–2022 and have stayed elevated in a lot of categories since. If your flat-rate book hasn't been touched since before that, you're almost certainly running thinner than your spreadsheet says.
Mixing overhead into COGS distorts everything downstream — owner salary, office staff, truck insurance belong below the gross profit line, not folded into job costs, or you'll never see your true production economics.
And ignoring small jobs is a mistake dressed up as efficiency. A $180 drain clear that takes 45 minutes and $15 in materials is running above 80% gross margin. High-frequency small jobs are margin engines; the error is pricing them as if they carry the same overhead allocation as a big remodel.
Pull the last 90 days of job data and calculate gross margin by job type — not as a blended total. If you're running ServiceTitan, Jobber, or Housecall Pro, this report already exists; you just haven't run it. If you're working off a spreadsheet, sort completed jobs by category, subtract labor and materials from revenue for each group, and divide. What you find will tell you more about the health of the business than any industry benchmark, and it'll show you exactly where to focus first — usually one service category is quietly propping up two or three others.