Stretch Film Roll Length Guide: How to Read Roll Specifications

A stretch film roll is correctly specified by three numbers together - width, thickness in microns, and net film weight - not by length alone. Understanding all three lets you calculate real roll length, compare rolls fairly, and choose the right film for your pallet load without wasting material or over-spending.

Author: Le Van Thang, Director of ICD Vietnam. This question comes up almost every day on the warehouse floor. When a customer asks how many metres a roll contains, what they really need to know is how many pallets it will wrap. Length is just one part of the specification - the rest of this guide shows you how to read all of it.

1. Why the answer is never just one number

Looking only at the length printed on a label can lead to a poor purchasing decision. A very long roll that is too thin tears easily, forces you to add extra wrapping layers, and costs more in the end. Length is only part of the story.

A complete stretch film specification - the one that actually determines wrapping performance - has three core elements:

1. Width (roll width): determines the coverage per pass around the load.
2. Thickness (micron): determines strength and puncture resistance.
3. Net film weight: determines the actual amount of film you receive.

Only when you understand all three can you answer “how long is this roll?” accurately.

2. How to read a stretch film roll specification

Take the most common specification on the market as an example: 50 cm x 17 mic x 4.0 kg (core 1.0 kg)

Width

• 50 cm (500 mm) is the roll width. This is the standard size for both hand wrapping and machine wrapping of pallets.

Thickness - micron (mic)

• 17 mic is the film thickness. This is a critical figure.
  • Thin film (12-17 mic): suited to light, uniform loads with no sharp edges.
  • Thicker film (20-23 mic and above): suited to heavy, bulky loads with sharp corners.

Gross weight, core weight, and net film weight

• 4.0 kg is the gross weight of the full roll including the cardboard core.
• Core 1.0 kg is the weight of the cardboard core alone.
• Net film weight = 4.0 kg - 1.0 kg = 3.0 kg.

So how long is the roll?

Roll length is calculated from the net film weight, thickness, width, and the density of PE film (approximately 0.92 g/cm3). The formula can be complex, but the quick-reference table below estimates common roll lengths for 50 cm wide film:

As shown above, the same net weight produces fewer metres when the film is thicker.

3. Film quality matters more than length

A high-quality LLDPE roll of 250 m can wrap more pallets than a low-grade LDPE roll of 300 m. The difference is stretch ratio.

High-quality machine stretch film can pre-stretch up to 200-300%. That means 1 metre of film can extend to 3-4 metres during wrapping while still maintaining holding force. This is the true measure of cost efficiency, not the nominal length on the label.

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