Construction Companies: How to Calculate Your Payroll Costs (2026)

Managed payroll by headcount for a construction company

10 employees: $450 a month, $5,400 a year; 25 employees: $1,125 a month, $13,500 a year; 50 employees: $2,250 a month, $27,000 a year; 100 employees: $4,500 a month, $54,000 a year. Every row is $45 per employee per month, all-inclusive, inside the payroll software you already use, with no monthly minimum, so the per-employee cost is the same at 10 as at 100. Nothing in the construction company setup, prevailing wage compliance, certified payroll, union vs non-union and seasonal crew cycles, is billed as an add-on.

The employer-side tax that rides on every construction company wage

At the May 2025 national median for construction laborers, $47,120 a year or about $23 an hour, the employer share of Social Security and Medicare is $3,605 per employee per year and FUTA is $42 after the state credit, before state unemployment at the assigned rate. Those costs are the same whoever runs payroll; the calculator question is only who does the work and who carries the error.

For per diem allowances paid for travel away from home on or after October 1, 2025, the IRS high-low substantiation rates are $319 per day for high-cost localities and $225 for all other localities in the continental United States, of which $86 and $74 are treated as paid for meals. The incidental-expenses-only rate is $5 per day.

The in-house line in the calculation

BLS OEWS May 2025: payroll and timekeeping clerks, national median $58,260, mean $59,630. Add roughly 30 percent for benefits and employer taxes, about $75,738, before the software that person runs, and set it against the headcount rows above. Managed payroll stays under that loaded figure until about 140 employees.