What is the labor cost per part formula?

Labor cost per part equals Operators times Loaded Rate times Cycle Time, divided by 3,600. Operators is the head count at the station, Loaded Rate is the fully burdened hourly cost in dollars per hour, and Cycle Time is seconds per good part. The 3,600 converts seconds and dollars-per-hour into dollars-per-part. Two operators at $42/hr with a 30-second cycle yields $0.70 per part.

How do I calculate the loaded labor rate?

Start with the base hourly wage, then add employer-paid burden: payroll taxes (FICA, FUTA, SUTA), health and retirement benefits, workers comp, and an allocated share of indirect overhead. That burden typically adds 25 to 40 percent. A $30 base wage often becomes a $40 to $42 loaded rate. Get the exact multiplier from accounting rather than guessing, since it directly scales every per-part number.

What is a good labor cost per part benchmark?

There is no universal number because it depends on the part's selling price. Use a ratio: on commodity machined or molded parts, direct labor above roughly 20 to 30 percent of piece price signals a candidate for automation or line rebalancing. In the example, $0.70 labor on a part selling for a few dollars is fine, but the same $0.70 on a $1.50 part is a margin problem.

Why is my labor cost per part higher than expected?

Usually one of three things: you used the loaded rate correctly but Cycle Time includes idle or wait time, you counted a full operator when they tend two machines, or the base wage crept up. Recheck the stopwatch study against good-part output only. If one operator runs two stations, use Operators equals 0.5. A 30-second cycle mistakenly logged as 45 seconds inflates cost by 50 percent.

Do I use seconds or minutes for cycle time in this formula?

Use seconds, because the constant 3,600 is the number of seconds in an hour and it cancels the per-hour unit in Loaded Rate. If your cycle time is in minutes, either convert to seconds first (multiply by 60) or swap the divisor to 60. A 30-second cycle stays as 30 with a 3,600 divisor; a 0.5-minute cycle needs a 60 divisor to reach the same $0.70.

What is the difference between labor cost and machine hour rate?

Labor cost per part captures only the human time at the station: operators times loaded wage times cycle time. Machine hour rate captures the equipment's ownership, maintenance, tooling, and utilities per running hour. They are additive, not interchangeable. A fully loaded piece price adds the $0.70 labor to the machine cost for the same cycle, plus material. Quoting labor alone understates true cost on capital-heavy operations.

Cost and Quoting

Labor Cost Formula

Labor cost per part uses loaded labor rate and cycle time to show how much direct labor goes into each unit. Use it when building a quote, comparing automation ROI, or benchmarking labor efficiency.

Formula

Labor Cost per Part = (Operators x Loaded Rate x Cycle Time) / 3,600

Variables

Operators: Number of direct labor operators assigned to the operation
Loaded Rate: Hourly wage plus all burden costs (benefits, taxes, overhead allocation) in $/hr
Cycle Time: Time to produce one part at the station, in seconds

Understanding the Labor Cost Formula

This formula isolates the direct labor content in a single part, separate from material and machine cost. On the shop floor it answers a blunt question: what does one operator-minute at this station actually add to the piece price? Multiplying Operators by Loaded Rate by Cycle Time and dividing by 3,600 converts an hourly staffing cost into a per-unit number you can drop straight into a quote. It exposes whether a manual operation is bleeding margin or whether a slow cycle is hiding real labor waste.

Pull Loaded Rate from accounting, not payroll. It must include the base wage plus benefits, employer taxes, and allocated overhead, which usually lands 25 to 40 percent above the raw wage. Cycle Time comes from a stopwatch study or the PLC part counter, measured in seconds per good part at that station. The 3,600 converts seconds and dollars-per-hour into dollars-per-part. Watch for shared operators tending two machines: charge a fraction of a person, so Operators might be 0.5, not 1.

In the worked case, two operators at $42/hr with a 30-second cycle give $0.70 per part. Compare that against the part's total cost: if labor is more than 20 to 30 percent of the piece price on a commodity part, automation or line balancing is worth studying. Falling cycle time or dropping to one operator moves the number fast. Use it to justify a robot: if a $0.70 manual cost drops to $0.15, the annual volume tells you the payback.

Worked Example

Two operators at a $42/hr loaded rate run a station with a 30-second cycle time.

Labor cost per part = (2 x $42 x 30) / 3,600
= $2,520 / 3,600
= $0.70 per part

Result: $0.70 per part

Common Mistake

Using straight wages instead of loaded rate. Benefits and employer taxes typically add 25-40% to the base wage. Using only wages understates labor cost and makes quotes unprofitable.

Frequently Asked Questions

What is the labor cost per part formula?: Labor cost per part equals Operators times Loaded Rate times Cycle Time, divided by 3,600. Operators is the head count at the station, Loaded Rate is the fully burdened hourly cost in dollars per hour, and Cycle Time is seconds per good part. The 3,600 converts seconds and dollars-per-hour into dollars-per-part. Two operators at $42/hr with a 30-second cycle yields $0.70 per part.
How do I calculate the loaded labor rate?: Start with the base hourly wage, then add employer-paid burden: payroll taxes (FICA, FUTA, SUTA), health and retirement benefits, workers comp, and an allocated share of indirect overhead. That burden typically adds 25 to 40 percent. A $30 base wage often becomes a $40 to $42 loaded rate. Get the exact multiplier from accounting rather than guessing, since it directly scales every per-part number.
What is a good labor cost per part benchmark?: There is no universal number because it depends on the part's selling price. Use a ratio: on commodity machined or molded parts, direct labor above roughly 20 to 30 percent of piece price signals a candidate for automation or line rebalancing. In the example, $0.70 labor on a part selling for a few dollars is fine, but the same $0.70 on a $1.50 part is a margin problem.
Why is my labor cost per part higher than expected?: Usually one of three things: you used the loaded rate correctly but Cycle Time includes idle or wait time, you counted a full operator when they tend two machines, or the base wage crept up. Recheck the stopwatch study against good-part output only. If one operator runs two stations, use Operators equals 0.5. A 30-second cycle mistakenly logged as 45 seconds inflates cost by 50 percent.
Do I use seconds or minutes for cycle time in this formula?: Use seconds, because the constant 3,600 is the number of seconds in an hour and it cancels the per-hour unit in Loaded Rate. If your cycle time is in minutes, either convert to seconds first (multiply by 60) or swap the divisor to 60. A 30-second cycle stays as 30 with a 3,600 divisor; a 0.5-minute cycle needs a 60 divisor to reach the same $0.70.
What is the difference between labor cost and machine hour rate?: Labor cost per part captures only the human time at the station: operators times loaded wage times cycle time. Machine hour rate captures the equipment's ownership, maintenance, tooling, and utilities per running hour. They are additive, not interchangeable. A fully loaded piece price adds the $0.70 labor to the machine cost for the same cycle, plus material. Quoting labor alone understates true cost on capital-heavy operations.