A job gets quoted, won, and delivered on time, and still makes nothing. The labor and materials were covered. But the shop rent, the supervisor’s salary, the machine depreciation, and the electric bill never made it into the price. That shortfall is manufacturing overhead, and when it is not counted and spread correctly, the jobs that look profitable quietly pay for the ones that are not.
What Counts as Manufacturing Overhead, and What Doesn’t
Manufacturing overhead is every factory cost that is not direct material or direct labor. If the cost happens inside the shop but cannot be traced to a single unit, it belongs here.
Indirect labor counts, including supervisors, maintenance staff, quality inspectors, and material handlers. Facilities costs count, including factory rent or mortgage, utilities, property taxes, and shop insurance. Equipment costs count, including depreciation, repairs, machine maintenance, and small tools. Supplies and consumables count as well, including lubricants, shop rags, safety gear, and cutting fluids.
What does not belong in manufacturing overhead is anything that happens outside the factory door. Sales team salaries, marketing spend, office costs, and back-office G&A are period costs, not product costs. Folding them into a job’s price overprices every bid. Leaving real overhead out underprices every bid. Both mistakes are common, and both eventually show up in the margin.
The Overhead Rate That Actually Matters
Manufacturing overhead gets built into price through an allocation rate, one number that spreads total overhead across the work. The simplest version divides total annual factory overhead by total direct labor hours, or machine hours.
Consider a job shop running $250,000 a year of overhead, made up of $60,000 in rent, $24,000 in utilities, $40,000 in depreciation, $76,000 in indirect labor, and $50,000 in supplies and insurance. Its crew logs 10,000 direct labor hours a year, putting the overhead rate at $25 per direct labor hour.
A job using 40 labor hours and $2,500 of material now carries $1,000 of manufacturing overhead. Fully loaded, that job costs $4,300, not the $3,300 of direct cost visible on the shop floor. Price it at direct cost plus 20 percent, and the “win” loses money before a single invoice clears.
The same arithmetic applies to under-applied overhead. If the shop only logs 8,000 hours against that same $250,000 of fixed cost, the true rate climbs to over $31 an hour. Running the lower rate all year means every job under-absorbs its share of manufacturing overhead, a variance that lands on the income statement at year end regardless of whether anyone saw it coming.
What the Owner Should Test
A few checks keep manufacturing overhead honest. Every indirect cost needs to be captured, which means walking the shop and inventorying what the floor actually consumes, since missed overhead functions as an invisible price cut.
The allocation driver needs to match reality. A labor-hour rate punishes machine-heavy jobs and subsidizes hands-on ones. If machines drive the cost, allocating manufacturing overhead by machine hours, ideally by department, produces a far more accurate picture.
Applied-versus-actual variance needs regular reconciliation, comparing overhead absorbed into jobs against the real number monthly rather than waiting until year end. And pricing itself needs to be checked against fully loaded cost. Pulling one recent job and rebuilding its true cost, manufacturing overhead included, reveals quickly whether the quote actually covered it. If it did not, either the rate or the pricing approach is broken.
The Bottom Line
The jobs a shop wins are supposed to make money. That only happens when manufacturing overhead is counted completely and spread the way the shop actually runs, not the way a simplified rate assumes it does.
