How to Calculate Your Contractor Overhead Rate (With Real Examples)

A plumbing company with four technicians and $180,000 in annual overhead needs to recover $45,000 per technician just to break even on business costs, before anyone earns a dollar of profit. If that number isn't built into every service call price, the company is quietly losing money on every job.

This is the overhead problem that affects most contractor businesses. The calculation itself isn't complicated. What's hard is doing it honestly and making sure the result ends up in your prices.

What Overhead Rate Actually Means for Contractors

Your overhead rate is the cost of running your business expressed as a ratio, either to your revenue or to your billable labor hours. It represents the portion of every dollar you collect (or every hour you bill) that goes toward keeping the lights on, the trucks running, the insurance paid, and the office functioning.

Overhead is not job cost. Job cost is what you spend on a specific project: materials, direct labor on that site, any subcontractors or rentals tied to that job. When the job is done, those costs stop.

Overhead keeps running whether you have jobs or not. Your liability insurance renews in January whether December was your best month or your worst. Your truck payment is due whether you're slammed or slow. Your office manager needs to be paid even during a weather week when no crews are in the field.

Because overhead is fixed and ongoing, it has to be calculated as a rate and applied to every job, every service call, every quote you write. Contractors who don't do this are funding their overhead out of what should be profit, and wondering why the bank account never matches the revenue number.

The Two Overhead Formulas Contractors Use

There are two standard ways to express your overhead rate. Which one you use depends on how you bill.

Formula 1: Overhead as a Percentage of Revenue

Overhead Rate (%) = Total Annual Overhead / Total Annual Revenue x 100

This method is common for general contractors and remodelers who price jobs as a total project price. If your annual overhead is $300,000 and you generate $1,500,000 in revenue, your overhead rate is 20%.

That means 20 cents of every dollar you collect goes toward overhead costs. To break even on overhead, a $100,000 job needs to include $20,000 in overhead recovery before you add profit.

Formula 2: Overhead Per Billable Labor Hour

Overhead Rate ($/hr) = Total Annual Overhead / Total Annual Billable Labor Hours

This method is more useful for service contractors who price by the hour or who build job prices from a labor-hour estimate. It tells you exactly how many dollars of overhead need to be recovered for every hour a technician is in the field.

If your overhead is $180,000 and your team bills 6,000 hours per year, your overhead burden is $30 per billable labor hour. That $30 has to be in your hourly rate before you even get to labor cost, materials, or profit.

Both methods are valid. The per-hour method tends to be more precise for service trades because it ties overhead recovery directly to the billable unit. The percentage-of-revenue method is more practical for project-based work where you're pricing lump sums.

What a Good Overhead Rate Looks Like by Trade

Overhead rates vary significantly by trade based on crew sizes, equipment requirements, office needs, and how much non-billable time the business model requires.

If your overhead rate is lower than your trade benchmark, one of two things is true: you're running an unusually efficient operation, or you're not counting all of your overhead. The second is more common.

If your overhead rate is higher than your trade benchmark, that's not automatically bad, but it does mean your prices need to reflect it. A GC with 30% overhead isn't unviable. A GC with 30% overhead who's pricing like one with 18% overhead is losing money on every job.

How to Build Your Overhead List

The most important step in calculating your overhead rate is building an honest, complete list of what goes in it. Most contractors who do this for the first time find costs they weren't tracking.

Facilities: Office or shop rent, utilities, storage. Any space not tied to a specific job site.

Insurance: General liability, workers' compensation premium, commercial auto, umbrella policy.

Vehicles and Equipment: Loan or lease payments, registration, insurance, shop tools and small equipment not purchased for a specific job, fleet software.

Licensing and Compliance: Contractor licenses, bond premiums, required continuing education.

Office and Administration: Office staff wages (estimators, project coordinators, bookkeepers), accounting fees, legal fees, software subscriptions (estimating, project management, accounting, CRM), office supplies.

Marketing and Sales: Advertising spend, website costs, lead generation services, trade association memberships, branded uniforms.

Owner and Management Time: If you spend significant time on estimating, sales, or administration that isn't billed to a job, that time has a cost. Price it at your market-rate salary for that role. Contractors who skip this step discover the real cost when they eventually hire someone to replace them in that function.

Add these up annually. That total is your overhead number.

Worked Example: A Plumbing Contractor with 4 Technicians

Here's how this calculation works for a real-world scenario.

Business: residential and light commercial plumbing service company, 4 field technicians, owner working primarily in estimating and operations.

Annual overhead:

Billable labor hours: 4 technicians x 48 weeks x 40 hours = 7,680 gross hours. Subtract 20% for drive time, callbacks, and non-billable time: 6,144 billable hours.

Overhead per billable hour: $280,000 / 6,144 = $45.57/hr

Every hour a technician spends on a job needs to recover $45.57 in overhead before the company makes any profit, before labor wages, before materials.

Overhead as a percentage of revenue: If annual revenue is $1,100,000: $280,000 / $1,100,000 = 25.5%

Now they have two usable numbers. For hourly service work, they build $45.57/hr into their fully-loaded labor rate. For project bids, they apply 25.5% to estimated direct cost. Either way, overhead is recovered automatically on every job.

Three Common Overhead Mistakes

1. Underestimating your own labor. Many contractor-owners don't count their own time as overhead because they're not writing themselves a check for estimating or managing the business. If you spend 15 hours a week on estimating and business development, that time has a real cost. Price it as overhead at your market rate for that role, or you'll eventually need to hire someone to replace you with no budget for it.

2. Not updating your rate annually. Insurance premiums go up. You add a truck. You hire an office manager. Any of these changes affects your overhead rate. Contractors who calculate their rate once and never revisit it are often using a number that's significantly below their actual current overhead. Build a recurring calendar reminder to recalculate every January.

3. Mixing personal and business overhead. Personal cell phone, partial home office costs, personal vehicle use. This is common for small contractors and creates real problems when calculating your rate. If personal costs are inflating your overhead number, your calculated rate won't reflect your actual business overhead. Keep the two clean in your books before running this calculation.

How Overhead Rate Connects to Your Bid Price

Once you know your overhead rate, you need to build it into bids correctly.

The sequence: estimate direct job cost (materials + direct labor for this specific project), apply overhead recovery (multiply direct cost by your overhead percentage, or add overhead per billable hour to your labor hours), then add target profit margin on top of the full cost, not just direct cost.

The common mistake: applying a markup to direct job cost and assuming it covers both overhead and profit. Often it doesn't.

Example: direct cost is $20,000, overhead rate is 22%, target net margin is 12%.

• Direct cost: $20,000
• Overhead recovery (22%): $4,400
• Total cost: $24,400
• Price for 12% net margin: $24,400 / (1 - 0.12) = $27,727

A contractor who simply marks up the $20,000 by 25% gets to $25,000. That sounds like it leaves room for profit, but 22% overhead on a $25,000 job is $5,500. They only recovered $4,400. They're $1,100 short on overhead before profit enters the picture.

This is the math that causes contractors to look at their revenue and not understand where the money went.

For more on the markup vs. margin difference, the Pricing Strategy Calculator walks through this calculation so you can set your price from your actual cost structure.

Know Your Number Before the Next Bid

The overhead rate calculation requires you to know your actual costs. If your books are current, it takes about an hour. Once you have your rate, build it into every quote template so it applies automatically, not as something you remember to add sometimes.

If you want to check whether your current pricing covers your costs and what net margin you're actually working with, the Pricing Strategy Calculator and Break-Even Calculator are built for exactly this.

Also worth reading: How to Calculate Overhead for a Construction Business covers the formula applied to construction companies with field crews and project-based bidding.

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*This content is for informational purposes only and does not constitute financial or tax advice. Consult a qualified professional for your specific situation.*