Overtime as a Percentage of Total Labor Cost

What Is Overtime as a Percentage of Total Labor Cost?

Overtime as a percentage of total labor cost measures how much of your total labor spending goes toward overtime hours. It takes every dollar you spent on overtime — including the premium portion — and expresses it as a share of your total labor cost for the period.

This metric does something that raw overtime hours alone cannot: it normalizes overtime against the size of your workforce. A business with 50 employees spending $40,000 on overtime has a very different situation than a 10-person operation spending the same amount. Expressing it as a percentage gives you a number that's comparable across time periods, departments, and businesses of different sizes.

The Formula

Overtime as a % of Total Labor Cost = (Total Overtime Cost / Total Labor Cost) x 100

Definitions

Total overtime cost is the full amount paid for all overtime hours during the period. This includes both the regular rate portion and the overtime premium. If an employee earning $20 per hour works 10 hours of overtime, the total overtime cost is $300 (10 hours x $30 per hour), not just the $100 premium.

Total labor cost is all wages and salaries paid during the period — regular time, overtime, and any other direct labor compensation. It does not include benefits unless you want to track overtime as a percentage of fully loaded labor cost, which is a separate but also valid calculation.

A Worked Example

A mechanical insulation contractor has the following labor data for the past quarter:

• Total regular wages paid: $380,000

• Total overtime wages paid: $47,500

• Total labor cost: $427,500

Overtime as a % of Total Labor Cost = ($47,500 / $427,500) x 100 = 11.1%

This contractor is spending more than one dollar out of every ten on overtime. Whether that's acceptable depends on the nature of the work and how the number has trended over time — but 11% is high enough to warrant a closer look.

What Is a Normal Overtime Percentage?

There is no universal benchmark for overtime as a percentage of labor cost because it varies significantly by industry, seasonality, and business model. That said, some general reference points are useful:

For most non-construction businesses, overtime above 5% of total labor cost is worth monitoring. Above 10% suggests overtime has become structural rather than occasional.

For construction and contracting, higher overtime percentages are more common due to project deadlines, weather delays, and labor shortages. Percentages in the 8% to 15% range are not unusual during peak periods. The concern arises when elevated overtime persists across multiple quarters without a clear project-driven explanation.

The most useful benchmark is your own history. Track this number quarterly and establish what your normal range looks like. Deviations from your own baseline are more meaningful than comparisons to industry averages.

The Difference Between Occasional and Structural Overtime

Not all overtime is a problem. Occasional overtime driven by a specific project deadline, a weather delay, or a short-term labor shortage is a normal part of running a contracting business. The cost is real but the cause is identifiable and temporary.

Structural overtime is different. It happens when overtime becomes a routine part of how work gets done — when crews regularly work 50-hour weeks not because of a specific deadline but because the business is chronically understaffed relative to its workload. Structural overtime is expensive in ways that go beyond the premium pay. Fatigued workers make more mistakes and have more accidents. Chronic overtime drives turnover, which then creates more labor shortages, which drives more overtime. It becomes self-reinforcing.

The distinction matters because the fixes are different. Occasional overtime is managed at the project level. Structural overtime requires a workforce planning decision — whether to hire, subcontract, limit new work, or restructure how crews are deployed.

Why Overtime Costs More Than You Think

The overtime premium — the extra 50% above the regular rate — is the visible cost. But overtime carries hidden costs that push the true expense higher.

Workers compensation premiums are calculated on total wages including overtime. If your workers comp rate is $12 per $100 of payroll and you pay $47,500 in overtime wages, that's an additional $5,700 in workers comp cost attributable to overtime.

Productivity tends to decline during overtime hours. Research consistently shows that output per hour worked falls as total hours increase, particularly beyond 50 hours per week. You are paying a premium rate for hours that produce less than a standard hour of work.

Safety incidents increase with fatigue. Overtime-related fatigue is a documented contributor to workplace accidents. Each incident carries costs beyond the immediate workers comp claim — lost productivity, investigation time, potential OSHA involvement, and the impact on your experience modifier.

Using This Metric to Diagnose Problems

A rising overtime percentage over several quarters is a signal worth investigating before it becomes a crisis. When you see it climbing, ask:

Is it concentrated in a specific crew, department, or job classification? Concentrated overtime often points to a staffing gap in a specific role rather than a company-wide problem.

Is it tied to specific projects or customers? Some projects are simply more demanding. If the same customers or project types consistently drive overtime, that's a pricing and estimating issue as much as a workforce issue.

Is it seasonal? Construction overtime often spikes in summer and fall. If your overtime percentage spikes and then normalizes, it may be manageable. If it never fully normalizes, the seasonal peak has become your new baseline.

Is turnover contributing to it? High turnover creates temporary labor shortages that get covered with overtime from remaining employees. If your turnover rate and overtime percentage are both rising, they are likely feeding each other.