How to calculate labor cost, overhead and break-even per square foot for a countertop shop

A shop's real cost per square foot comes from three numbers. The first is the loaded labor cost per productive hour: wages plus payroll taxes, workers' comp and benefits, divided by the hours people actually spend on jobs, commonly about 1.4 to 1.8 times the hourly wage. The second is labor cost per square foot, which is production payroll divided by finished square feet shipped, commonly $12 to $20 for stone. The third is overhead per square foot, all non-job costs divided by finished square feet, commonly $15 to $30 for small and mid-size shops. Those ranges are rules of thumb from shop practice, not survey data, so work out your own. Add material with waste and consumables, and you have the cost a price must cover. Break-even volume is monthly fixed cost divided by what each square foot contributes after its variable costs.

Where the money goes in a countertop job

Before the formulas, it helps to see the shape of a healthy shop's costs. As a share of revenue, common ranges from shop practice are:

These ranges are rules of thumb, not a standard or a published survey. They move with the product mix, with volume and with how much of the work is subcontracted. What matters is knowing your own numbers, which the rest of this article works out.

Direct costs and overhead: what goes where

Direct costs belong to a specific job. They go on that job's cost sheet:

• Slab material, including the part of the slab the job wastes (see waste factor in bids).

• Consumables used on that job.

• Direct labor: hours of templaters, CNC and saw operators, fabricators, polishers and installers spent on the job, including travel to it.

• Job-specific extras: a subcontracted plumber, crane rental, special freight.

Overhead is everything else the shop needs to exist:

• Rent or mortgage, property tax, building maintenance.

• Equipment loan payments or depreciation, and machine maintenance contracts.

• Utilities: power for saws and CNCs, water and water treatment, slurry disposal.

• Insurance other than workers' comp (general liability, commercial auto, property and equipment).

• Office, sales, estimating and management salaries, including the owner's pay for time not spent producing.

• Vehicles not charged to jobs, software, phones, accounting, legal, marketing.

• Silica compliance: air monitoring, medical surveillance, respirator program, dust and water systems upkeep. OSHA's respirable crystalline silica standard for shops (29 CFR 1910.1053, PEL 50 µg/m³ as an 8-hour average, action level 25 µg/m³) makes this a real, recurring cost. See OSHA silica compliance.

Workers' comp and payroll taxes on production staff go into the loaded labor rate, not overhead, so that they follow the labor hours.

Step 1: loaded labor cost per productive hour

The wage on the pay stub is not what an hour of labor costs the shop. Two corrections turn it into a usable number.

Add the labor burden. The employer pays these on top of wages:

For most shops the burden adds 25 to 45% to wages. That is a rule of thumb, but it fits national data: in June 2026, benefits, including paid leave and legally required payroll taxes, were 30.0% of private-industry compensation, according to the Bureau of Labor Statistics. That is about 43% on top of wages.

Divide by productive hours, not paid hours. A full-time employee is paid for about 2,080 hours a year. Take away paid holidays and vacation (80 to 120 hours) and time that no job can be charged for, such as cleanup, maintenance, meetings, training and waiting for material. A well-run shop gets roughly 1,650 to 1,850 productive hours per person (rule of thumb). Put the two corrections together and an hour of productive labor commonly costs about 1.4 to 1.8 times the wage: 1.25 × 2,080 ÷ 1,850 = 1.41 at the low end, and 1.45 × 2,080 ÷ 1,650 = 1.83 at the high end.

Worked example, an illustration with assumed rates: an installer earning $24 per hour. For comparison, the national median wage for tile and stone setters was $26.77 an hour in May 2025 (Bureau of Labor Statistics).

The 8% comp rate is an assumption for the arithmetic, not a typical rate. Put in your own policy's rate. The productive-hour figure is the one to use for pricing. Pricing labor at the bare $24 wage undercosts every labor hour by more than a third.

Step 2: labor cost per square foot

There are two ways to get labor per square foot. Use both, because they check each other.

The top-down method. Divide a year's loaded production payroll by the finished square feet invoiced in that year. Example: a shop with eight production staff (a templater, a saw operator, a CNC operator, two fabricators and three installers) and a loaded production payroll of $496,000 ships 34,000 sq ft of finished tops. Labor is $496,000 ÷ 34,000 = $14.59 per sq ft.

The job method. Add the person-hours a typical job takes. For a 45 sq ft kitchen, shops commonly log something like:

At $38.48 per productive hour, 11 to 21.5 hours is $423 to $827, or about $9 to $18 per sq ft. If the top-down number is much higher than the job number, hours are going somewhere that isn't being tracked: remakes, rework, waiting, or jobs that took far longer than planned.

Labor per square foot varies by material and job. Quartzite, porcelain and sintered stone take longer to cut and polish than quartz. Decorative edges, many cutouts, mitered aprons and waterfalls add hours that have little to do with area. That is why labor-heavy items should be priced per linear foot or per piece on top of the base rate. See pricing methods and pricing add-ons.

Step 3: overhead per square foot

Overhead rate = total overhead for a period ÷ finished square feet invoiced in the same period.

Use finished square feet (what you bill), not slab square feet bought or square feet templated. Use actual volume, not what the shop could do at full capacity. Fixed costs don't shrink when volume drops, so a capacity-based rate underprices every job in a slow year.

Example annual overhead for the same shop (an illustration; the insurance line and the others are assumed, not benchmarks):

Overhead rate: $600,000 ÷ 34,000 sq ft = $17.65 per sq ft. In a slow year of 28,000 sq ft, the same costs come to $21.43 per sq ft.

For small and mid-size retail shops, overhead commonly runs $15 to $30 per finished square foot (rule of thumb, no published survey). High-volume builder shops spread fixed costs over far more footage and run lower. Small custom shops with showrooms run higher. Volume moves the number more than any single expense.

Include the owner's pay. An owner who takes no salary and calls what's left "profit" is pricing below cost. Put a market wage for the owner's time into production labor for the hours spent producing and into overhead for the hours spent managing and selling.

Equipment is volume-sensitive. A $180,000 CNC depreciated over 7 years is about $25,700 a year, plus perhaps $6,000 for maintenance, or $31,700. Spread over 34,000 sq ft that is $0.93 per sq ft. In a shop shipping 8,000 sq ft a year it is $3.96. Before buying a machine, check the volume it needs to be cheaper than the work it replaces. See equipment planning.

Insurance belongs in the rate, not on the quote. Build liability and property insurance into overhead and workers' comp into the labor rate. Customers read an "insurance" line as padding. If a job carries unusual risk, such as a very heavy island, a crane lift or a walk-up, charge a named line like "complex installation". See insurance and risk.

Recalculate the rate at least quarterly. Insurance renewals, new hires and rent increases arrive mid-year.

Step 4: put the job cost together

Now the full cost of a job can be built line by line. Take a 45 sq ft kitchen in a mid-range quartz that fits on one jumbo slab.

To reach a 15% net profit, divide by 0.85: $2,886 ÷ 0.85 = $3,395, or about $75 per sq ft. On that price the gross margin (price minus material, consumables and direct labor) is $1,303, or 38%.

If the market for this quartz is $70 per sq ft, the job still covers cost but earns about 8%. If it is $60, the job loses money and the shop has to find the gap in yield, labor hours or overhead, or stop selling that product at that price. For pricing decisions and margin targets, see margins and markup.

Your shop hourly rate

Service calls, repairs, time-and-materials commercial work and change orders need an hourly rate. Build it the same way:

1. Loaded labor per productive hour: $38.48.

2. Overhead per productive hour: total overhead ÷ total production hours. With eight production staff at 1,730 hours, $600,000 ÷ 13,840 = $43.35.

3. Cost per hour: $81.83.

4. Add margin: at 15%, $81.83 ÷ 0.85 = about $96 per hour.

As a rule of thumb (no published survey), stone shops bill roughly $75 to $110 per hour on this kind of work, before materials and trip fees. A rate below your cost per hour means every service call loses money, even when the customer pays.

Break-even volume

Break-even is the volume at which revenue covers all costs and profit is zero.

Break-even square feet per month = monthly fixed costs ÷ contribution per square foot

Contribution per square foot is the price minus the costs that rise and fall with each job. For the example shop:

• Monthly fixed costs (overhead): $600,000 ÷ 12 = $50,000.

• Variable cost per sq ft: material $28.89, consumables $3.00, direct labor $14.59, total $46.48.

• Contribution at $75 per sq ft: $28.52.

• Break-even: $50,000 ÷ $28.52 = about 1,750 sq ft per month, or roughly 39 kitchens of 45 sq ft.

This version treats production labor as variable. In reality hourly staff are paid whether or not there is work, so in a slow month labor behaves like a fixed cost and the true break-even is higher. A cautious owner runs the numbers both ways. With production payroll counted as fixed ($50,000 + $496,000 ÷ 12 = about $91,300 a month, and a contribution of $75 − $28.89 − $3.00 = $43.11 per sq ft), the same shop needs about 2,120 sq ft a month.

For a new shop, break-even math also decides how much working capital is needed to survive the first year. See starting a fabrication business.

Piece rate and subcontracted labor

Some shops pay fabricators per square foot or per linear foot of edge, and many pay install crews per job. That turns part of labor into a truly variable cost per square foot, which makes pricing simpler. The rules still apply: under the federal Fair Labor Standards Act, piece-rate employees must earn at least minimum wage for all hours worked, and for hours over 40 in a week they are owed an extra half of their average hourly rate (total weekly pay divided by hours worked). California additionally requires separate pay for rest and recovery periods and other nonproductive time (Labor Code 226.2). Subcontracted crews move the cost to a per-job invoice, but you still need their real cost to compare. See crews, tools and pay.

Common mistakes

• Using the bare wage instead of the loaded cost per productive hour.

• Leaving out non-productive time, so every job looks faster than it is.

• Dividing overhead by capacity instead of actual output.

• Leaving the owner's pay out of costs.

• One labor rate per square foot for every job, so complex jobs lose money.

• Forgetting travel time and vehicle cost on template and install trips.

• Setting the numbers once and never updating them. Wages, insurance and rent all rise, and a price list built on two-year-old costs is underpriced.

Where software helps

The formulas are simple. Keeping them current is the hard part. In Stonify, the general ledger gives the overhead totals for the rate calculation, with a profit and loss statement by location if the shop has several. Reports can total square feet installed per week, which is the denominator for both labor and overhead rates. Each service can carry a cost estimate, and the project Cost & Profit Report compares what the job was sold for with the landed cost of its allocated slabs and the estimated cost of its services, so the shop can see which job types actually make money.

FAQ

What is a typical labor cost per square foot for stone countertops? For fabrication plus installation, loaded labor commonly runs $12 to $20 per finished square foot in a mid-size shop (rule of thumb), higher for quartzite, porcelain and complex edges, and higher in high-wage metros.

What is a good overhead rate for a countertop shop? Many small and mid-size retail shops run $15 to $30 per finished square foot, or roughly 20 to 30% of revenue (rules of thumb). Lower is better only if it isn't achieved by leaving out the owner's pay or skipping maintenance.

Should overhead be allocated per job, per square foot or per hour? Per square foot works well when jobs are similar. Per labor hour or machine hour is fairer when job complexity varies a lot, because a complex 40 sq ft kitchen uses more shop capacity than a simple one. Per job is the crudest and overcharges small jobs.

How much more than the wage does an employee cost? About 1.25 to 1.45 times the wage per paid hour, and about 1.4 to 1.8 times per productive hour once holidays and non-billable time are counted. Both are rules of thumb; national data show benefits, including paid leave and payroll taxes, averaging about 43% on top of wages (BLS, June 2026).

How often should I recalculate my costs? Overhead quarterly, labor rates at least once a year and after any raise or new hire, and material costs whenever supplier prices change.

Sources

• U.S. Bureau of Labor Statistics, Employer Costs for Employee Compensation, June 2026 (September 9, 2026)

• Social Security Administration, Contribution and benefit base ($184,500 for 2026; $192,300 for 2027, announced October 14, 2026)

• IRS, Topic no. 759, Form 940, Employer's annual federal unemployment (FUTA) tax return (page last reviewed September 24, 2026)

• U.S. Department of Labor, FUTA credit reductions (2025 final; 2026 potential, final list due November 10, 2026)

• U.S. Department of Labor, Significant provisions of state unemployment insurance laws, effective January 2026

• KFF, 2026 Employer Health Benefits Survey (October 22, 2026)

• U.S. Bureau of Labor Statistics, Occupational Outlook Handbook: Flooring installers and tile and stone setters (May 2025 wages; page modified September 14, 2026)

• 29 CFR 778.111, Pieceworker regular rate and overtime (Fair Labor Standards Act regulations)

• California Department of Industrial Relations, Piece-rate compensation (Labor Code 226.2) FAQs

• OSHA, Respirable crystalline silica standards (29 CFR 1910.1053)