A KPI for plumbers, or Key Performance Indicator, is a measurable figure showcasing how effectively or ineffectively your business reaches its target goals.
This guide covers the KPIs a plumbing company should track, the formula for each, and how often to review them. Professional plumbing work is the foundation of the business, and these figures show whether that work is producing a profit.
Key Takeaways
- Seasonal revenue: the money customers pay in each season, before any costs, shows when slow and peak periods arrive.
- Gross margin: (revenue – cost of goods sold) ÷ revenue shows whether jobs are priced above what they cost to complete.
- Monthly profit margin: (revenue – fixed costs – variable costs) ÷ revenue shows whether the business is profitable in a given month.
- Lead performance: revenue per lead, lead booking rate, cost per lead, and cost per booked job show whether marketing spend becomes work.
- Service performance: average ticket, first-time fix rate, callback rate, and technician utilization show job quality and labor productivity.
- Customer satisfaction: a post-job score and a review response habit show how customers rate completed work.
- Review cadence: weekly for operations, monthly for financials, and annually for growth and seasonality.
Plumbing KPI Summary Table
| KPI | Formula | What it tells you |
|---|---|---|
| Seasonal revenue | Customer payments received in a season | When slow and peak periods arrive |
| Gross margin | (Revenue – cost of goods sold) ÷ revenue × 100 | Whether jobs are priced above their direct cost |
| Monthly profit margin | (Revenue – fixed costs – variable costs) ÷ revenue × 100 | Whether the business is profitable that month |
| Year-over-year revenue growth | (This year’s revenue – last year’s revenue) ÷ last year’s revenue × 100 | Whether the business is growing or shrinking |
| Revenue per lead | Revenue from booked jobs ÷ number of leads | What each lead is worth |
| Lead booking rate | Booked jobs ÷ leads × 100 | How many leads become work |
| Average ticket | Revenue ÷ completed jobs | Revenue earned per job |
| First-time fix rate | Jobs resolved on the first visit ÷ completed jobs × 100 | Diagnostic skill and truck stock readiness |
| Callback rate | Jobs needing a return visit for the same problem ÷ completed jobs × 100 | Quality problems and warranty cost |
| Technician utilization | Billable hours ÷ paid hours × 100 | How much paid time earns revenue |
| Customer satisfaction score | Average of post-job survey scores | How customers rate completed work |
1) Seasonal Revenue: When Slow and Peak Periods Arrive
Seasonal revenue is the money customers pay for services and products in a given season, before subtracting any costs.
When calculating seasonal or annual sales revenue, remember this figure refers only to the money coming in from customers paying for the services or products you make available.
Seasonal revenue doesn’t refer to adjusted income after you’ve paid employees, bought supplies, and covered operating costs.
Tracking revenue by month and grouping the months into seasons shows when the lulls and peaks arrive. Seasonality is strongest for plumbers who service regions with freezing temperatures.
In warm-climate markets, the pattern may be weaker or driven by different factors, so the monthly data defines the seasons.
Once the slow and peak seasons are identified, these options can smooth the valleys:
- Flag aging water heaters during service calls. ENERGY STAR advises that a water heater more than 10 years old is worth replacing before it fails, since emergency replacements can cost more and limit choices. Technicians can check the unit’s age on every call and offer a planned replacement in a slow month.
- Offer maintenance agreements. A maintenance agreement is a recurring paid plan that generates revenue between emergency calls. Its effect on seasonality depends on how many customers enroll and how many visits are scheduled outside the peak.
- Train technicians to present upgrade options. Training gives technicians a consistent way to present plumbing upgrades during slow-season visits.
- Schedule planned work in slow months. Inspections and planned installations move demand out of the peak.
2) Gross Margin: The Formula and What Counts as Cost
Gross margin is revenue minus cost of goods sold, divided by revenue, expressed as a percentage.
Gross margin = (Revenue – Cost of goods sold) ÷ Revenue × 100
For a plumbing company, cost of goods sold is the direct cost of completing jobs, such as the materials and supplies installed on those jobs.
Decide once whether technician wages and job fuel sit in cost of goods sold, then apply that rule every year. Year-over-year comparisons only hold when the definition stays constant.
Supplies that were purchased but not yet used do not belong in the period’s cost of goods sold. IRS Publication 334 (2025) states that businesses accounting for inventory have their inventory valued at each year’s start and end when cost of goods sold is calculated.
The same publication lets small business taxpayers instead treat inventory as non-incidental supplies and deduct the cost in the year the items are first used or consumed.
Business growth is a separate figure from gross margin, and it is measured with year-over-year revenue growth.
Year-over-year revenue growth = (This year’s revenue – Last year’s revenue) ÷ Last year’s revenue × 100
A company can raise gross margin while revenue falls, so you need to track both figures. Keep annual gross margins in one record so each year can be compared with the last.
Gross Margin vs. Net Margin
| Gross margin | Net margin | |
|---|---|---|
| Formula | (Revenue – cost of goods sold) ÷ revenue × 100 | (Revenue – cost of goods sold – fixed and other operating costs) ÷ revenue × 100 |
| Costs subtracted | Direct job costs only | Direct job costs plus fixed and operating costs |
| What it tells you | Whether jobs are priced above what they cost to complete | Whether the whole business is profitable |
Gross margin comparisons between companies are unreliable when the companies define cost of goods sold differently.
3) Monthly Profit Margin: Fixed, Variable, and Semi-Variable Costs
Monthly profit margin is net margin calculated for a single month. It equals revenue minus fixed costs and variable costs, divided by revenue, where variable costs include the materials counted in cost of goods sold.
Monthly profit margin = (Revenue – Fixed costs – Variable costs) ÷ Revenue × 100
The U.S. Small Business Administration defines fixed costs as costs that do not change with production or services. Its examples include rent, salaries, insurance, and interest.
The same guidance classifies fuel, repairs, and monthly telephone service as semi-variable, meaning a mix of fixed and variable parts. It recommends separating semi-variable costs into fixed and variable portions where possible.
| Cost type | Behavior | Plumbing examples |
|---|---|---|
| Fixed | Does not change with the number of jobs | Shop or office rent, insurance, salaried staff pay, loan interest |
| Variable | Rises and falls with job volume | Materials and supplies, hourly or commission pay that scales with jobs, per-lead advertising fees |
| Semi-variable | Has a fixed base plus a variable portion | Vehicle fuel, fleet repairs, phone service |
Advertising follows the same behavior test. A fixed monthly marketing retainer is a fixed cost, while spend billed per lead or per click moves with volume and is variable or semi-variable.
Salaried pay is fixed under the SBA’s examples, while hourly or commission pay that rises with job volume fits the definition of a variable cost.
When material prices change, update the variable cost figures for that month so the profit margin reflects current prices.
Fixed costs set the floor for each month: revenue must cover them before any profit appears, so knowing the fixed total shows how many jobs a month the business needs to break even.
4) Lead and Service Performance
Revenue per lead equals the revenue from booked jobs divided by the number of leads received in the same period.
Calculating it monthly works well, and the period for revenue and leads must match. The other lead and service figures below show where revenue per lead is being gained or lost.
- Revenue per lead: revenue from booked jobs ÷ number of leads.
- Lead booking rate: booked jobs ÷ leads × 100.
- Cost per lead: marketing spend ÷ number of leads.
- Cost per booked job: marketing spend ÷ number of booked jobs.
- Average ticket: revenue ÷ number of completed jobs.
- First-time fix rate: jobs resolved on the first visit ÷ completed jobs × 100.
- Callback rate: jobs needing a return visit for the same problem ÷ completed jobs × 100.
- Technician utilization: billable hours ÷ paid hours × 100.
- Revenue per technician: revenue ÷ number of technicians in the same period.
Cost per lead rewards lead volume, while cost per booked job shows whether those leads turn into work.
A low revenue per lead traces back to three levers: the booking rate, the average ticket, and the mix of services sold. Training technicians to present upgrade options is one way to raise the average ticket.
Better routing changes labor and fuel cost per job, so it appears in gross margin and technician utilization rather than revenue per lead.
5) Customer Satisfaction and Online Reviews
Customer satisfaction is measured by asking every customer the same one or two questions after each job and averaging the scores by month. Review responses are a separate signal, because they influence prospective customers.
As of February 2026, BrightLocal’s survey of 1,002 US adults found that 80% of consumers are likely to use a business that responds to all of its reviews, and 42% are unlikely to use a business that never replies.
In the same survey, 89% of consumers expect owners to respond to reviews, 19% expect a same-day reply, and 81% expect one within a week. Templated or generic replies make 50% of consumers unlikely to choose a business.
Keep in mind these figures describe US consumer attitudes toward local businesses in general, so they cover more industries than just plumbing. However, it’s reasonable to derive two review KPIs from them: the share of reviews that receive a reply (replied reviews ÷ total reviews) and the time to reply.
Which KPIs to Track by Business Size
A solo plumber needs four figures to start: monthly revenue, gross margin, average ticket, and lead booking rate.
Each technician added makes technician utilization, revenue per technician, first-time fix rate, and callback rate necessary, because the owner no longer sees every job.
A company with a large commercial or new-construction share should calculate gross margin by service line. A single blended figure hides which type of work carries the margin.
How Often to Review Each KPI
Weekly reviews suit operational figures, and monthly reviews suit financial figures. This is a recommended cadence as opposed to a fixed rule, and busy shops may combine the weekly and monthly reviews.
| Cadence | KPIs | Purpose |
|---|---|---|
| Weekly | Lead booking rate, average ticket, technician utilization, first-time fix rate, callback rate, new reviews and replies | Catch service and marketing problems while they are small |
| Monthly | Revenue, gross margin, monthly profit margin, fixed and variable costs, revenue per lead, cost per booked job, customer satisfaction score | Close the books and compare to prior months |
| Annually | Year-over-year revenue growth, annual gross margin, seasonal revenue pattern | Compare years and plan for the seasons |
Reply to new reviews within one business day so the reply time stays inside the window most consumers expect. Record the review count and average star rating at each monthly review so changes in reputation show up alongside the financial figures.
Common KPI Mistakes and When KPIs Mislead
- Counting unused supplies as cost. Materials bought but not yet installed overstate cost and understate margin for the period.
- Changing the cost of goods sold definition between years. The comparison then measures the definition change.
- Reading gross margin as profit. A healthy gross margin can coexist with a negative monthly profit margin when fixed costs are high.
- Treating all advertising as fixed. Per-lead and per-click spend moves with volume.
- Tracking cost per lead without cost per booked job. Cheap leads that do not book inflate the appearance of efficiency.
- Reading averages without context. Average ticket rises when the mix shifts toward larger jobs, even if pricing per job is unchanged.
- Judging a KPI on a single month. Seasonal swings make single-month comparisons misleading, so compare the same month year over year.
KPIs are least reliable at very low job volumes, where one large job or one callback moves a percentage sharply.
What to Do When a KPI Moves the Wrong Way
A KPI that moves the wrong way calls for checking its inputs before changing pricing or staffing.
Confirm the period and cost definitions are unchanged, then identify which component moved: leads, booking rate, average ticket, or cost. Change the operation that drives that component, and review the KPI again at the next monthly close.
Author: Nolen Walker
Nolen Walker is the founder of Plumbing Webmasters and the creator of DataPins™, a Local SEO platform for plumbing companies. He has over 16 years of experience helping plumbing businesses grow through organic search, Google Maps, and AI-driven visibility.
Nolen is the author of A Complete SEO Guide for the Plumbing Small Business Owner. He also hosts The Plumbing SEO Podcast on Spotify.
