What is unit cost in manufacturing?

Unit cost is the total cost to produce one good part, summing Material, Labor, Overhead, Setup per Unit, and a Scrap Allowance. In the example it builds from a $4.143 base cost and divides by yield to reach $4.27 per good unit. It is the floor for quoting, so any selling price must clear it plus margin. It captures scrap because you only get paid for shippable parts.

How do I calculate labor and overhead cost per unit from an hourly rate?

Multiply the loaded rate by cycle time in seconds, then divide by 3,600 to convert to hours. Labor at $38/hr with a 45-second cycle is $38 x 45 / 3,600 = $0.475 per part. Overhead at $55/hr uses the same math: $55 x 45 / 3,600 = $0.688. The 3,600 is seconds per hour. Always use burdened rates that include benefits and facility cost, not base wages.

How does batch size affect setup cost per unit?

Setup per Unit is total setup cost divided by batch size, so it falls as batches grow. At $240 setup over 500 parts, it is $0.48 each. Drop the batch to 250 and it doubles to $0.96, adding $0.48 to every unit. Raise it to 1,000 and it halves to $0.24. This is why small runs quote high and why setup reduction pays off most on short batches.

Why do I divide by yield instead of just adding the scrap percentage?

Because scrapped parts still consume full material, labor, and overhead, so surviving parts must carry that loss. Dividing base cost by yield does this correctly. At 3% scrap you divide $4.143 by 0.97, giving $4.27, which is about 3.1% more, not exactly 3%. Simply adding 3% would under-recover. The gap widens with scrap: at 10%, dividing by 0.90 adds 11.1%, far more than a flat 10%.

What cycle time units does the unit cost formula use?

Cycle time enters in seconds, then the divide-by-3,600 converts it to hours so it pairs with an hourly rate. The example uses 45 seconds: $38 x 45 / 3,600. If your cycle time is in minutes, either multiply by 60 to get seconds or divide the rate by 60 instead of 3,600. Mixing units here is a frequent error that can inflate or deflate labor cost tenfold.

What is the difference between unit cost and unit price?

Unit cost is what the part costs you to make, $4.27 in the example, covering material, labor, overhead, setup, and scrap. Unit price is what you charge the customer, which is unit cost plus margin. If you want 25% gross margin on a $4.27 cost, you price around $5.69, not $4.27 x 1.25 applied loosely. Quoting at cost with no margin means you cover expenses but earn nothing.

Cost and Quoting

Unit Cost Formula

Unit cost rolls material, labor, overhead, setup, and scrap into a single per-part number. Use it before submitting a quote, comparing process options, or evaluating a make-vs-buy decision.

Formula

Unit Cost = Material + Labor + Overhead + Setup per Unit + Scrap Allowance

Variables

Material: Raw material cost consumed per good part, in dollars
Labor: Loaded labor rate (including burden) x cycle time / 3,600
Overhead: Machine or overhead rate x cycle time / 3,600
Setup per Unit: Total setup cost divided by batch size
Scrap Allowance: Base cost divided by yield to account for scrapped units

Understanding the Unit Cost Formula

Unit cost collapses everything it takes to make one good part into a single dollar figure you can quote against. It sums Material, Labor, Overhead, Setup per Unit, and a Scrap Allowance. In the example those roll from $2.50 material and $0.475 labor up to a $4.143 base, then divide by yield to reach $4.27 per good unit. That last division matters: you are not pricing the parts you make, you are pricing the parts you can actually ship after scrap.

Each input has its own source and units. Material is dollars of raw stock per good part. Labor is the loaded rate times cycle time divided by 3,600 to convert seconds to hours: $38 x 45 / 3,600 = $0.475. Overhead uses the same time math with the machine rate, giving $0.688. Setup per Unit is total setup cost over batch size, so $240 / 500 = $0.48, which shrinks as batches grow. Always use loaded, burdened rates, not base wages.

The final number is a floor, not a price. $4.27 is cost before margin; your quote adds markup on top. Watch how setup and scrap move it. Halving the batch to 250 doubles setup to $0.96 per unit and pushes cost well past $4.27, which is why small jobs quote high. A jump in scrap from 3% to 8% divides base cost by 0.92 instead of 0.97, adding real money. Requote whenever batch size or yield shifts materially.

Worked Example

Material is $2.50. Labor rate is $38/hr, cycle time is 45 seconds. Overhead rate is $55/hr. Setup cost is $240 for a batch of 500. Scrap rate is 3%.

Labor = $38 x 45 / 3,600 = $0.475
Overhead = $55 x 45 / 3,600 = $0.688
Setup per unit = $240 / 500 = $0.48
Base cost = $2.50 + $0.475 + $0.688 + $0.48 = $4.143
Good-unit cost = $4.143 / (1 - 0.03) = $4.27

Result: $4.27 per good unit before margin

Common Mistake

Forgetting to divide by yield. A 3% scrap rate adds about 3.1% to cost, not 3%. The formula divides the base cost by the yield fraction, which is the correct way to recover scrap losses through pricing.

Frequently Asked Questions

What is unit cost in manufacturing?: Unit cost is the total cost to produce one good part, summing Material, Labor, Overhead, Setup per Unit, and a Scrap Allowance. In the example it builds from a $4.143 base cost and divides by yield to reach $4.27 per good unit. It is the floor for quoting, so any selling price must clear it plus margin. It captures scrap because you only get paid for shippable parts.
How do I calculate labor and overhead cost per unit from an hourly rate?: Multiply the loaded rate by cycle time in seconds, then divide by 3,600 to convert to hours. Labor at $38/hr with a 45-second cycle is $38 x 45 / 3,600 = $0.475 per part. Overhead at $55/hr uses the same math: $55 x 45 / 3,600 = $0.688. The 3,600 is seconds per hour. Always use burdened rates that include benefits and facility cost, not base wages.
How does batch size affect setup cost per unit?: Setup per Unit is total setup cost divided by batch size, so it falls as batches grow. At $240 setup over 500 parts, it is $0.48 each. Drop the batch to 250 and it doubles to $0.96, adding $0.48 to every unit. Raise it to 1,000 and it halves to $0.24. This is why small runs quote high and why setup reduction pays off most on short batches.
Why do I divide by yield instead of just adding the scrap percentage?: Because scrapped parts still consume full material, labor, and overhead, so surviving parts must carry that loss. Dividing base cost by yield does this correctly. At 3% scrap you divide $4.143 by 0.97, giving $4.27, which is about 3.1% more, not exactly 3%. Simply adding 3% would under-recover. The gap widens with scrap: at 10%, dividing by 0.90 adds 11.1%, far more than a flat 10%.
What cycle time units does the unit cost formula use?: Cycle time enters in seconds, then the divide-by-3,600 converts it to hours so it pairs with an hourly rate. The example uses 45 seconds: $38 x 45 / 3,600. If your cycle time is in minutes, either multiply by 60 to get seconds or divide the rate by 60 instead of 3,600. Mixing units here is a frequent error that can inflate or deflate labor cost tenfold.
What is the difference between unit cost and unit price?: Unit cost is what the part costs you to make, $4.27 in the example, covering material, labor, overhead, setup, and scrap. Unit price is what you charge the customer, which is unit cost plus margin. If you want 25% gross margin on a $4.27 cost, you price around $5.69, not $4.27 x 1.25 applied loosely. Quoting at cost with no margin means you cover expenses but earn nothing.