Thermoforming Scrap Rate Calculator
Compare gross sheet input with measured material retained in good finished parts to calculate the material loss rate.
Use a saved product specification (optional)
Enter your values
First time using this calculator?
Replace the example values with figures from your supplier sheet or measurements. Choose the unit beside each value. Results update as you type; fix any highlighted field before using the result.
GSM means grams per square metre. Net weight excludes the core and other packaging. MOQ means the minimum order quantity. An optional field can stay blank unless the result you need depends on it.
Prices keep the selected currency; changing its label does not convert an exchange rate. Save or export the result after checking your inputs.
Gross-input scrap rate
Measure input and good output over the same production boundary. This calculation does not distinguish trim, rejects, startup losses or recovered regrind.
Scrap % = (gross input kg − actual good part g × quantity ÷ 1,000) ÷ gross input kg × 100
(500 − 20 × 20,000 ÷ 1,000) ÷ 500 × 100 = 20%Saved calculations stay in this browser. No account or cloud backup is created.
Save to a product project (optional)
Choose or create a saved product project ↗This is an illustrative example. Saved or transferred values must be checked against your job.
Calculated from your inputs. Confirm specifications with your supplier.
How sensitive is this result to your assumptions?
Vary one input and inspect gross-input scrap rate
All other entered inputs stay fixed. Ranges are your scenarios, not statistical confidence or supplier performance predictions. This uses the same validated calculator engine.
The formula, made clear.
Good output is the actual weight of one accepted part multiplied by accepted quantity. Subtract that retained mass from gross sheet input, then divide by the input mass. The balance can include trim skeleton, startup material and rejects. Whether any of it is recovered or reprocessed is a separate material-flow question.
How to use this calculator
- 01
Enter gross sheet mass consumed for the measured run.
- 02
Enter actual finished-part weight and accepted part count for the same run.
- 03
Review loss mass and its percentage of gross input.
A calculation you can check
The example reconciles a measured sheet input with the mass retained in accepted trays to reveal the unretained material fraction.
- Gross sheet input weight
- 500 kg
- Actual good part weight
- 20 g
- Good parts produced
- 20000 units
(500 − 20 × 20,000 ÷ 1,000) ÷ 500 × 100 = 20%Check the displayed formula and units against your quotation. Use measured GSM, net weight and actual layout dimensions where available. Default densities are planning assumptions, not certified material properties. Calculated cost does not certify strength, compatibility or safe loading.
Method, units and material assumptions ↗