Here is a story that plays out in thousands of small construction businesses every year. A contractor finishes a strong year — trucks are busy, jobs close out, clients are happy. Every single job showed a profit on the estimate. But when the accountant runs the numbers, the business barely broke even, or worse, lost money. The owner is baffled. Where did it go?
The answer is almost always overhead — the cost of being in business that never shows up on any single job. Rent, insurance, the truck payment, the phone, the bookkeeper, your own salary when you are in the office instead of the field. If you are not deliberately recovering these costs on every job, you are quietly donating them back to your clients. This article walks through how to calculate your real overhead rate and, more importantly, how to make sure it lands in every bid.
Direct Costs vs. Overhead: Drawing the Line Correctly
Before you can recover overhead, you have to know what counts as overhead. This trips up more contractors than you would expect. The rule is simple: a direct cost is any expense you can trace to a specific job. Overhead is every other cost of keeping the doors open.
- Direct costs — materials, subcontractors, field labor wages, equipment rental for a specific job, permits, dumpster fees. If the job disappeared, so would the cost.
- Overhead (indirect) costs — office rent, general liability insurance, accounting and legal fees, vehicle payments and fuel for the estimator, software subscriptions, marketing, office staff, and your own non-field salary.
The gray zone is where people get it wrong. A project manager who splits time across five jobs is overhead unless you are tracking their hours per job. Small tools and consumables — blades, fasteners, caulk — are technically direct but so annoying to track per job that most contractors roll them into overhead or a flat consumables percentage. Pick a consistent treatment and stick with it, because moving costs between buckets year to year makes your overhead rate meaningless.
If you cannot point to the specific job a dollar was spent on, it is overhead. And overhead only gets recovered if you price it in on purpose.
Calculating Your Overhead Rate the Right Way
The overhead rate is the percentage you must add to direct costs to cover your indirect expenses. The math is not complicated, but the inputs have to be honest. Start with a full trailing 12 months of numbers — not a good quarter, not last month, a full year that captures your slow season too.
Add up your total annual overhead. Say it comes to $180,000 — that includes your office, insurance, admin salary, vehicles, software, and a reasonable owner's salary for the time you spend not swinging a hammer. Now add up your total annual direct job costs. Say that is $900,000 in materials, labor, and subs across all your jobs.
Your overhead rate is overhead divided by direct costs:
- $180,000 ÷ $900,000 = 0.20, or 20%
That means for every dollar of direct cost on a job, you need to add 20 cents just to cover overhead — before you have made a single dollar of profit. A $50,000 direct-cost job needs $10,000 of overhead recovery baked in, bringing your break-even to $60,000. Bid that job at $58,000 with a “profit” you calculated off direct costs alone, and you just lost $2,000 while feeling good about it.
The Volume Trap That Destroys Your Rate
Here is the part nobody warns you about: your overhead rate depends on your volume, and volume is not guaranteed. Most overhead is fixed — your rent does not drop because you booked fewer jobs. So if you calculate a 20% rate based on $900,000 of volume and then only do $600,000 next year, your real overhead rate was never 20%.
Run the same $180,000 of overhead against $600,000 of direct costs and the rate jumps to 30%. Every job you priced at 20% overhead recovery was underpriced by a third of its overhead load. This is exactly how a slow year turns into a losing year even when your win rate on bids stays the same.
Two defenses. First, calculate your overhead rate off a conservative volume estimate, not your best year. If you are unsure whether next year holds, use last year's actual volume, not your optimistic pipeline. Second, watch your booked backlog through the year and recalculate mid-year if volume is trending down — you may need to raise your rate on new bids to stay whole.
Fixed overhead spread over fewer jobs means a higher cost per job. The contractors who survive slow years are the ones who raise their overhead recovery rate before the shortfall shows up in the bank account.
Ready to put this into practice? Download TrestleBook Free — it’s free and works offline.
Overhead and Profit Are Not the Same Thing
The old “10 and 10” shorthand — 10% overhead, 10% profit — has confused an entire generation of contractors, because both numbers are usually wrong and they serve completely different purposes. Overhead recovery keeps you solvent. Profit is what is left over to reward the risk of running the business, fund equipment, and build a reserve.
Keep them as separate line items in your own math, even if the client only sees one marked-up number. If you blend them, the first thing that gets cut when a client pushes back on price is your profit — and you will not even realize it is gone because it was never broken out. When you track overhead and profit separately, a price negotiation becomes a clear decision: “I can shave my profit margin to win this, but I cannot cut below my overhead recovery or I lose money.”
This same discipline of separating the cost of running the business from the profit you actually take home shows up in every kind of self-employment, not just construction. Freelancers and solo operators tracking their own effective rate with a tool like Stintly run into the identical trap — billing enough to cover the project but forgetting the cost of simply being in business. The math is the same whether you swing a hammer or write code.
Baking Overhead Into Every Bid
Knowing your rate is useless if it does not make it into the estimate. Build your bids from the bottom up in this order, every time:
- Sum your direct costs — materials, labor at fully burdened rates, subs, job-specific equipment and permits.
- Apply your overhead rate to those direct costs — 20% in our example.
- Add your profit margin on top of the overhead-loaded total, using margin math, not markup math, so the percentage actually lands where you think it does.
- Sanity-check against the market — if the number is wildly high, the problem is usually your overhead being too heavy for your volume, not your pricing being greedy.
The discipline here is refusing to skip step two under pressure. When a client is standing in front of you wanting a number, it is tempting to quote off direct costs plus “a little extra.” That little extra is almost never 20%. Keeping your direct costs organized and current is what makes step one fast enough that you never feel forced to shortcut the rest — tools like TrestleBook let you track job costs as they happen so your next estimate is grounded in what work actually cost you, not what you hoped it would.
Track Actuals So Next Year's Rate Is Real
Your overhead rate is only as good as the historical data behind it, and most contractors are working from a shoebox of receipts and a gut feeling. The fix is to capture costs in real time as they hit — every material run, every subcontractor payment, every hour of field labor coded to the right job. When your direct costs are clean, your overhead rate calculation is trustworthy, and the whole cycle tightens up.
This is where field-first tracking pays off. TrestleBook makes this easy with offline job cost tracking, so a crew lead can log a delivery or a change on-site without a signal, and it syncs when they are back in range. At year-end, you are not reconstructing your overhead from memory — you are dividing two numbers you already trust. The same principle applies to anyone managing recurring property expenses; landlords using KeyLoft to separate their operating costs from per-unit repairs are running the exact same discipline in a different industry.
You cannot manage what you do not measure. An overhead rate built on guessed numbers is just a more confident way to underprice.
Common Overhead Mistakes That Cost Real Money
- Leaving out your own salary — if you do not pay yourself a market wage for office and management time, your overhead looks artificially low and every bid is understated.
- Using a stale rate for years — insurance, rent, and software creep up. A rate you calculated three years ago is almost certainly too low today.
- Applying one blanket rate to wildly different jobs — a labor-heavy remodel and a material-heavy new build may need different treatment; some contractors recover overhead on labor hours instead of total direct cost for this reason.
- Forgetting seasonality — if you make 70% of your revenue in six months, your overhead runs all twelve. Price accordingly.
- Confusing markup and margin — a 20% markup is not a 20% margin, and blurring them quietly erodes both overhead recovery and profit.
Putting It All Together
Overhead is the silent killer of otherwise healthy construction businesses. It does not announce itself on any single job — it accumulates quietly across a whole year until the numbers do not add up and you cannot say why. The contractors who stay profitable are not the ones who bid highest or work hardest. They are the ones who know their real overhead rate, recalculate it when volume shifts, and refuse to let a single bid leave the office without it baked in.
Do the math this week. Pull your trailing twelve months, add up your overhead honestly — salary included — divide it by your direct costs, and look at the number. If it is meaningfully higher than what you have been adding to bids, you just found the gap between the profit on paper and the balance in the bank. Close it on your next estimate, and keep tracking your actuals so next year's number is even sharper.