GIFSQ Tools · Module 10 — Packaging & Shelf-Life · Tool 181 of 500
Find a packaging film thickness from a weighed sample, its area and the polymer density — plus the gauge and mil equivalents used on film specifications.
Try sample values — fills the form with the worked example below.
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Thickness (µm)
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Thickness (gauge)
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Thickness (mil)
Equation: Thickness (µm) = mass (g) ÷ [area (cm²) × density (g/cm³)] × 10,000. Gauge = µm ÷ 0.254; mil = µm ÷ 25.4.
Method: Gravimetric film thickness: weigh a known area of film and divide by density. 1 gauge = 0.25 µm (100 gauge = 25.4 µm); 1 mil = 25.4 µm (ASTM D374 micrometer practice is the direct method).
Assumptions: the sample is a single uniform layer of one polymer; density is the value for that polymer at room temperature; edges are cut square.
Limitations: multilayer, coated or embossed films give an average thickness only; density varies between polymer grades, so use the supplier value for the exact grade.
Rounding: thickness to 2 decimal places; gauge and mil to 2 decimal places; intermediates unrounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Method: Gravimetric film thickness: weigh a known area of film and divide by density. 1 gauge = 0.25 µm (100 gauge = 25.4 µm); 1 mil = 25.4 µm (ASTM D374 micrometer practice is the direct method).
Assumptions: the sample is a single uniform layer of one polymer; density is the value for that polymer at room temperature; edges are cut square.
Limitations: multilayer, coated or embossed films give an average thickness only; density varies between polymer grades, so use the supplier value for the exact grade.
Rounding: thickness to 2 decimal places; gauge and mil to 2 decimal places; intermediates unrounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Worked example: A 0.5 g sample of 100 cm² film with density 0.92 g/cm³: thickness = 0.5 ÷ (100 × 0.92) × 10,000 = 54.35 µm (213.97 gauge, 2.14 mil).
Enter values above to see results.
Typical food films: 12–25 µm snack wrap, 25–50 µm pouch film, 50–100 µm heavy-duty film. Tool 181 of 500 — GIFSQ
