What Every Contractor Gets Wrong About Overhead

A contractor overhead calculation sounds like accountant homework, and that's exactly why so many good tradespeople get wrecked by it. You can be the best roofer in the county, book plenty of work, price your labor and materials right, and still end the year wondering where the money went. It went to overhead you never loaded into your bids.

Overhead is every dollar you spend to be in business that isn't tied to one specific job. And if it's not baked into your prices, it's coming straight out of your take-home. Every time.

The costs everybody forgets to load

Ask a contractor what a job costs and they'll rattle off materials and labor. That's it. But your business burns money whether or not a single job is running that week.

Here's the overhead that quietly eats profit:

• Trucks and equipment. Payments, fuel, insurance, maintenance, tools that wear out. That $600 truck payment doesn't pause on a slow week.
• Insurance. General liability, workers comp, commercial auto. Easily $500 to $1,500 a month depending on your trade and state.
• Your phone, software, and office. CRM, estimating tools, accounting software, the phone plan, rent or the home office.
• Your own admin time. The hours you spend at night writing estimates and chasing invoices instead of on a roof. That time has a cost even if you don't cut yourself a check for it.
• Marketing. Trucks lettering, the website, yard signs, ad spend, referral thank-yous.
• The stuff that isn't billable. Driving to the supply house, a callback that isn't warranty, an estimate that didn't close. Real hours, no revenue.

Add those up for a month and most solo operators or small crews land somewhere between $6,000 and $15,000 in overhead. That's the number that has to get covered by the jobs, before you've made a dime of profit.

Per-hour vs per-job: how to actually spread it

Knowing your total overhead is step one. Getting it onto each bid is where the calculation lives, and there are two clean ways to do it.

The per-hour method. Take your monthly overhead and divide it by your billable field hours in a month. Say overhead is $10,000 and your crew bills 320 hours a month. That's $31.25 of overhead per billable hour. Every hour you quote has to carry that on top of the labor cost, or the job doesn't pull its weight.

The percentage method. Add up a year of overhead and a year of direct job costs (materials plus labor). Divide overhead by direct costs. If overhead is $120,000 and direct job costs are $480,000, your overhead rate is 25 percent. So every job gets marked up 25 percent to cover overhead before profit even enters the picture.

Use whichever fits how you bid. Time-heavy service work, the per-hour rate is cleaner. Material-heavy jobs like a reroof, the percentage method tends to track better. Pick one and apply it to every single bid, no exceptions. The job you "do a favor on" without loading overhead is the one that costs you.

Why a profitable-looking job actually loses money

This is the trap, and it fools smart people. You bid a bathroom remodel. Materials run $4,000, labor $3,000. You charge $9,000. Looks like a clean $2,000 profit, right?

Now load overhead. Say that job ties up your crew for 60 hours. At $31.25 an hour of overhead, that's $1,875 of business cost that job has to carry. Your real profit isn't $2,000. It's $125. And if the job runs two days long, or you eat a material re-order, you're now paying the customer to let you remodel their bathroom.

A job is only profitable after it covers its share of overhead. Not before. The gap between "looked like $2,000" and "actually $125" is exactly where contractors go broke while staying busy. They see gross profit and think it's real profit. It isn't.

Recalculate it, don't set it and forget it

Overhead isn't a one-time number. Insurance renews higher. You add a truck. Fuel spikes. You hire an office person. Every one of those changes your rate, and if you're still bidding off last year's overhead figure, you're underpricing without knowing it.

Rerun the calculation every quarter, and any time a big fixed cost changes. It takes twenty minutes. Pull your overhead total, divide by your billable hours or job costs, and update the number you mark up by. Twenty minutes that keeps you from working all year for free.

The reason this matters so much is that overhead is invisible. Materials you can see on the receipt. Labor you see on payroll. Overhead just leaks, a little from every job, and you don't notice until the year's over and the bank account doesn't match how hard you worked. Load it into every bid on purpose, and the money finally shows up where it belongs, which is in your pocket.