Film yield in m²/kg: compare coverage instead of mass alone

The purchasing question

A kilogram quotation can hide a difference in coverage. When two qualified films serve the same area-based application, film yield helps explain why one produces more packs from the same purchased mass. Yield is a conversion of material quantity, not a guarantee of accepted production output.

Calculation method

Nominal yield in m²/kg = 1,000 ÷ GSM. Multiply that result by net purchased kilograms to find nominal area. To value coverage, multiply the kilogram price by GSM ÷ 1,000. Keep the film specification visible when comparing results.

Worked example

At 50 GSM, nominal yield is 20 m²/kg. At 60 GSM, it is about 16.6667 m²/kg. One thousand net kilograms represents 20,000 m² or approximately 16,667 m² respectively. At €3/kg, the area prices are €0.15/m² and €0.18/m².

The lighter film has a lower area cost in this example, but it is not automatically a suitable replacement. If actual useful yield is lower because of defects or converting losses, calculate cost per accepted area separately. Avoid rounding yield too early when planning a large order.

Checks before using the result

• Use net film kilograms rather than gross reel weight.
• Compare qualified specifications before calling the difference a saving.
• Separate nominal coverage from useful production coverage.

Common questions