Assembly Cost Calculator

Calculator Inputs

Order Quantity

Cycle Time Per Unit (minutes)

Number of Operators

Labor Rate Per Hour ($)

Machine Rate Per Hour ($)

Material Cost Per Started Unit ($)

Consumables Per Started Unit ($)

Quality Cost Per Good Unit ($)

Packaging Cost Per Good Unit ($)

Setup Cost ($)

Tooling Cost ($)

Overhead Rate (%)

Scrap Rate (%)

Rework Rate (%)

Downtime Factor (%)

Target Margin (%)

Reset

Example Data Table

Scenario	Order Qty	Cycle Time	Operators	Total Cost	Cost Per Unit	Quote Per Unit
Small Batch	250.00	8.20 min	2.00	$4,680.66	$18.72	$24.96
Standard Run	1,200.00	6.50 min	3.00	$21,745.75	$18.12	$23.23
Scaled Production	5,000.00	4.80 min	4.00	$85,682.29	$17.14	$21.42

These example values help validate the model and demonstrate how fixed costs shrink per unit as volume rises.

Formula Used

1. Units Started
Units Started = Order Quantity × (1 + Scrap Rate)

2. Adjusted Production Time
Adjusted Minutes = Units Started × Cycle Time × (1 + Rework Rate) × (1 + Downtime Rate)

3. Conversion Hours
Machine Hours = Adjusted Minutes ÷ 60
Labor Hours = Machine Hours × Operators

4. Cost Build
Labor Cost = Labor Hours × Labor Rate
Machine Cost = Machine Hours × Machine Rate
Material Cost = Units Started × Material Cost Per Unit

5. Total Assembly Cost
Total Cost = Labor + Machine + Material + Consumables + Quality + Packaging + Setup + Tooling + Overhead

6. Overhead and Quote
Overhead = (Labor Cost + Machine Cost) × Overhead Rate
Quoted Total = Total Cost ÷ (1 - Target Margin)

This model treats scrap as extra started units and treats rework and downtime as time multipliers. You can adapt the assumptions to your plant logic.

How to Use This Calculator

Enter the required good-unit order quantity.
Provide cycle time, operator count, and hourly labor rate.
Add machine, material, consumable, quality, and packaging costs.
Enter setup and tooling costs for the production run.
Set scrap, rework, downtime, overhead, and target margin percentages.
Click the calculate button to display totals above the form.
Review the graph, detailed table, cost per unit, and quote value.
Use the export buttons to save the result as CSV or PDF.

FAQs

1. What does this calculator estimate?

It estimates the full assembly cost for a production run. It includes labor, machine usage, materials, consumables, quality, packaging, setup, tooling, overhead, and a margin-based quote.

2. Why is scrap applied to units started?

Scrap means you must begin more units than you ship. That raises material use, consumables, and process time. Modeling started units gives a more realistic manufacturing cost.

3. How is rework treated here?

Rework is modeled as extra production time, not full material replacement. This is useful when most reworked units need added labor or machine time without needing completely new components.

4. What should I enter for overhead?

Use the percentage your business applies to conversion cost. Many teams load overhead onto labor and machine time because those activities drive utilities, supervision, plant support, and indirect expenses.

5. Can I use this for quoting customers?

Yes. The target margin field converts cost into a suggested quoted total and quoted unit price. That helps sales and operations align around a consistent quoting method.

6. Why do fixed costs matter more in small batches?

Setup and tooling are spread across fewer units in small runs. That increases cost per unit sharply. Larger batches dilute fixed charges and usually improve unit economics.

7. What is the difference between machine cost and labor cost?

Labor cost is based on operator hours and labor rate. Machine cost is based on adjusted machine hours and machine rate. Keeping them separate helps identify the main cost driver.

8. Can this model support different product families?

Yes. Change the unit costs, rates, times, and percentages for each family. Many manufacturers duplicate the template and save preset values for repeatable quoting workflows.