How to Calculate Labor Cost in Construction: A Step-by-Step Guide

Your crew wraps a finish carpentry job at 46 worker-hours. You bid 40. At the crew’s wages and estimated employer costs, that’s another $235 gone on a job that carried just $1,550 in the original labor budget.

Six extra hours. A 15% labor cost overrun.

To calculate labor cost in construction, you need three things: the hours the work should take, what you’ll pay the crew, and what those employees cost beyond their wages.

Construction Labor Cost = Base Wages + Employer Labor Burden

The arithmetic is straightforward. Estimating the hours is where contractors get into trouble.

How to Calculate Labor Cost in Construction in 6 Steps

Step 1: Break the Job Into Measurable Tasks

Say you’re bidding the finish carpentry on a small residential renovation.

The scope includes:

• 8 interior doors to hang
• 320 linear feet of baseboard
• 6 windows to case
• Final adjustments and cleanup

Don’t estimate the whole job as “two guys for two days.” Break it down.

Doors, baseboard, and casing have different installation requirements. Hanging a door in an existing opening with a crooked jamb takes longer than hanging one in a clean, square opening.

Walk the site. Check the openings, material locations, access, and existing finishes. Write down anything that will slow the crew.

A production rate based on new construction won’t necessarily hold up in an occupied renovation.

Step 2: Estimate Worker-Hours for Each Task

Use production rates from previous jobs to calculate the hours.

Worker-Hours = Quantity × Labor Hours per Unit

For our finish carpentry job:

All wages, production rates, and burden percentages in this article’s examples are fictional. Use your own records when estimating actual jobs.

The three hours for setup and cleanup get paid too.

Two carpenters working eight hours each produce 16 worker-hours. Not eight.

Estimate the worker-hours first. Figure out the calendar schedule after.

Step 3: Assign Hours to the Right Crew Members

Our job needs a lead carpenter and two installers.

The lead earns $38 per hour. The installers earn $28.

The lead handles layout, door adjustments, and the more demanding fitting work. The installers handle most of the baseboard and casing installation, and they’ll swap in where it makes sense.

Across the job, you estimate:

• Lead carpenter: 12 hours
• Installer 1: 14 hours
• Installer 2: 14 hours

That’s 40 worker-hours.

Keep the wage rates separate. The lead costs more per hour, and his time affects the total differently from the installers’ time.

Step 4: Calculate Employer Labor Burden

A carpenter earning $28 per hour costs the business more than $28.

The employer also pays expenses such as:

• Employer Social Security and Medicare taxes
• Federal and state unemployment taxes, where applicable
• Workers’ compensation insurance
• Employer-paid health and retirement benefits
• Paid leave costs, when included in the burden calculation

The IRS Employer’s Tax Guide explains federal employment tax responsibilities.

Use your payroll records to work out the additional employer costs.

Labor Burden Rate = Employer Labor Costs ÷ Base Wages × 100

If annual base wages are $250,000 and additional employer costs total $62,500:

$62,500 ÷ $250,000 = 25% labor burden

An installer earning $28 per hour then has an estimated burdened cost of $35 per paid hour.

There’s no standard burden percentage that works for every construction business. Your actual rate depends on payroll, insurance, benefits, and how you account for paid time.

Step 5: Account for Paid Time and Overtime

Your production estimate covers the work required. Your labor cost needs to cover the hours you’ll pay for.

Include job-specific setup, cleanup, material handling, and other necessary work. In our carpentry example, those hours already have their own allowance.

Check the schedule for overtime.

Under the federal Fair Labor Standards Act, covered, nonexempt construction employees generally receive at least 1.5 times their regular rate for hours worked beyond 40 in a workweek. State requirements can differ. See the Department of Labor’s construction fact sheet.

A carpenter earning a regular rate of $30 per hour who works 45 hours in a workweek would earn:

• 40 regular hours × $30 = $1,200
• 5 overtime hours × $45 = $225
• Total wages = $1,425

That calculation assumes $30 is the applicable regular rate for overtime purposes.

Check how overtime affects your employer costs, too. Some burden components use a different payroll basis. Confirm workers’ compensation treatment with your carrier rather than applying the same percentage to every overtime dollar.

Step 6: Calculate the Crew’s Total Labor Cost

Back to the finish carpentry job.

The crew has 40 estimated worker-hours. We’ll use a 25% labor burden for all three workers.

Base wages: $1,240.

Employer burden: $310.

Total estimated labor cost: $1,550.

Divide that by 40 worker-hours and you get an average burdened labor cost of $38.75 per worker-hour.

That’s the labor allowance you’ll carry into the job estimate.

You can run the numbers with Cinderblock’s free Labor Cost Calculator.

Calculate the two installers together using two workers at 14 hours each and $28 per hour. Then calculate the lead separately at 12 hours and $38 per hour. Add the results.

The calculator handles one wage and hours group at a time. It doesn’t automatically transfer your calculations into Cinderblock.

Calculate Your Crew’s Labor Cost

Labor Burden vs. Overhead: Know What You’re Counting

Labor burden covers the additional cost of employing your crew. Overhead covers expenses required to run the business.

An office manager’s salary, office rent, and general business software expenses typically belong in overhead. Employer payroll taxes and workers’ compensation on your field crew typically belong in labor burden.

Supervision depends on the work. A lead carpenter installing doors on one job belongs in that job’s labor cost. A supervisor overseeing several projects may have costs allocated across those jobs.

Pick a method and stick with it.

If you’ve already included paid leave in your labor burden, don’t add it again as a separate percentage.

Paid Hours vs. Productive Hours

Say you pay a carpenter for 2,000 hours during the year, but only 1,600 of those hours are productive job hours.

The other 400 paid hours cover leave, training, meetings, and other time that doesn’t produce billable work.

If wages and employer costs total $80,000 for the year, you get two hourly costs:

If you estimate jobs using productive installation hours alone, the $50 rate accounts for the additional paid time.

If you estimate using paid job hours and allocate other compensated time separately, you can work from the paid-hour rate.

Don’t apply the $50 productive-hour rate and then tack on the same leave and training costs again.

Our finish carpentry estimate uses burdened paid job hours, including the allowance for setup and cleanup. There’s no separate productive-hour adjustment.

Estimated vs. Actual Labor Cost: Where the $235 Went

The carpentry job is finished. The crew turns in its hours.

The two installers worked 16 hours each instead of 14. The lead worked 14 instead of 12.

Forty-six worker-hours against a 40-hour estimate.

Labor cost came in 15.2% over estimate.

The comparison uses the same straight-time wages and burden calculation as the original estimate. Any applicable overtime premium would need to be added.

Now check the production records.

Maybe the existing door openings needed more adjustment than expected. Maybe the baseboard took longer because the walls were out of square. Or maybe the installation rates were optimistic.

Find out.

If the overrun came from one difficult opening, record it as a job-specific problem. If the entire baseboard installation took longer than planned, your production rate needs another look.

Use Actual Hours to Improve the Next Bid

Keep the hours separated by task when possible.

Knowing the whole job ran six hours over budget is useful. Knowing that four of those hours went into door adjustments tells you what to look for on the next site visit.

When your crew records hours against jobs in Cinderblock, you can review the labor costs while the work is still fresh. That makes it easier to catch a bad estimate before you use the same numbers on another bid.

Cinderblock’s time tracking and job costing features are available on the Build plan. The Time Tracking and Job Performance pages explain how those tools work.

Three Labor Estimating Mistakes That Cost Contractors Money

Using the Billing Rate as the Labor Cost

Your installer earns $28 per hour. With 25% burden, he costs you $35 per paid hour.

You bill his labor at $75 per hour.

The $35 is the estimated cost to your business. The $75 is the customer rate, which needs to contribute toward overhead and profit.

Using the billing rate as your cost will distort the job estimate.

Using One Production Rate for Every Job

Installing 320 linear feet of baseboard in an empty new house is different from working around furniture and finished surfaces in an occupied renovation.

If your crew needed 16 worker-hours on the first job and 22 on the second, a single production rate won’t describe both very well.

Track the conditions that slow your crew down. Adjust your future estimates for those conditions.

Never Checking Actual Hours Against the Bid

A job runs six hours over. The next bid goes out using the same rates.

Then it happens again.

Compare estimated hours with actual hours by task. If the same work keeps running over budget, update the estimate instead of treating every overrun as bad luck.

How to Turn Labor Cost Into a Construction Quote

Your $1,550 labor allowance is one part of the finish carpentry quote.

Add the other job costs.

You have $3,000 in costs to recover.

For a 25% profit margin on the selling price after those allocated costs:

Selling Price = Total Cost ÷ (1 − Target Margin)

$3,000 ÷ 0.75 = $4,000

That leaves $1,000 of profit against the $3,000 cost basis, or 25% of the selling price.

A 25% markup on the same cost produces a $3,750 price and a 20% profit margin.

Check your numbers with Cinderblock’s free Job Pricing Calculator or Markup and Margin Calculator.

Once you’ve settled on a price, use the Contractor Estimate Generator to prepare the customer estimate.

Build Your Next Labor Estimate From the Last Job

The most useful labor rates come from jobs your crews have already completed.

For the next finish carpentry estimate, start with the quantities. Check your recorded hours for doors, baseboard, and casing. Adjust for the site’s conditions, assign the work to your crew, and add employer costs.

After the job, compare the estimate with the recorded hours.

If your crew keeps spending 46 worker-hours on work you bid at 40, the next estimate needs better numbers.

Keep those hours and costs with the job in Cinderblock so you’re not rebuilding the history from loose timesheets when it’s time to bid again.

Explore Cinderblock Time Tracking