Table of Contents
Reviewed and updated by ICD - Week 44/2026
Stretch film roll length = net film weight (core removed) divided by the density of 0.92 g/cm³, the width and the thickness. A hand-wrap roll 500 mm wide, 17 micron thick and weighing 1.8 kg net is about 230 m long. Because length depends on all three parameters, two rolls of the same weight can differ in length by more than a third. This article shows how to read the specification of a PE film roll and calculate the metres yourself.
1. The length formula
Film is a very thin block of PE, so its volume equals length times width times thickness, and its weight equals volume times density. Rearranged: length (m) = net weight (g) / (0.92 × width (cm) × thickness (cm)), then divide by 100 to get metres. A density of 0.92 g/cm³ is the typical value for LDPE and LLDPE (about 0.910 to 0.940 according to Wikipedia). For 500 mm film at 17 micron: each metre of length weighs 0.92 × 50 × 0.0017 = 0.0782 g/cm, which is 7.82 g per 1 m; 1,800 g net divided by 7.82 g/m gives about 230 m.
2. Reading the specification on a roll
A full specification gives width, thickness and weight, for example 50 cm × 17 mic × 4.0 kg (core 1.0 kg). A width of 50 cm is the most common size for hand-wrap film. Mic means micron, and 1 micron equals 0.001 mm. The weight printed on the label is usually the total including the paper core, so the true film weight is the difference: 4.0 minus 1.0 is 3.0 kg. Calculating with 4.0 kg would give a length about a third higher than reality.
ICD Vietnam hand-wrap film is 17 micron thick, 500 mm wide, with rolls weighing 2.1 to 5.0 kg including the core. ICD Vietnam machine-roll film is 20 to 30 micron thick, in rolls of 7 to 18 kg with a 76 mm core. The core makes up 6% to 24% of the roll weight depending on the code, so always ask for the net film weight instead of looking only at the total.
3. Quick length table (500 mm width)
| Net weight | 17 micron | 20 micron | 23 micron |
|---|---|---|---|
| 1.8 kg | 230 m | 196 m | 170 m |
| 2 kg | 256 m | 217 m | 189 m |
| 3 kg | 384 m | 326 m | 284 m |
| 4 kg | 512 m | 435 m | 378 m |
The figures above are calculated with the formula in section 1 and rounded to the metre. Real rolls differ by a few percent because of thickness and weight tolerances at the manufacturer; for an exact figure for a batch, follow that batch’s technical data sheet. At the same weight, thinner film is longer: a 14 kg roll of 17 micron film is about 35% longer than a 14 kg roll of 23 micron film, but thin film also carries less load.
4. Choose thickness by load, not only by metres
A longer roll is not necessarily a better deal. ICD Vietnam’s initial recommendation for pallet wrap: 15 to 17 micron for loads under 200 kg, 17 to 20 micron for 200 to 800 kg, 20 to 23 micron for 800 to 2,000 kg, and above 25 micron for special cases. Choosing film too thin to get more metres often makes it tear at the corners of the load and forces extra wraps; this is why the calculation should be based on load, not on metres.
5. Pre-stretch machines increase the effective metres of film
A wrapping machine with a pre-stretch unit stretches the film longer before wrapping. A stretch of 250% means the film becomes 3.5 times as long, so thin 23 micron film becomes about 6.6 micron when it hugs the load, and one metre of film on the roll covers about 3.5 metres on the pallet. So when comparing two machine rolls, compare the pre-stretch level as well, not only the nominal length. Hand-wrap film has no pre-stretch unit; you only pull it by hand, so efficiency is lower.
Frequently asked questions
How many metres is a 17 micron, 500 mm wide PE film roll weighing 1.8 kg?
About 230 m, calculated as the net weight divided by 0.92 g/cm³, the width and the thickness.
Does the weight printed on the roll include the core?
Usually yes. ICD Vietnam hand-wrap rolls weigh 2.1 to 5.0 kg including the core; the core makes up 6% to 24% depending on the code. Subtract the core before calculating the metres.
What is mic?
Mic is micron, one thousandth of a millimetre. ICD Vietnam hand-wrap film is 17 micron thick.
How do hand-wrap and machine film differ?
ICD Vietnam hand-wrap film is 17 micron thick, in small rolls. Machine-roll film is 20 to 30 micron thick, in rolls of 7 to 18 kg, and works with a pre-stretch unit.
What does 250% pre-stretch mean?
The film is stretched to 3.5 times its length before wrapping, so the same roll covers more pallets, but the thickness on the load drops accordingly.
Contact ICD Vietnam for advice
ICD Vietnam Industrial Manufacturing Co., Ltd.
Northern Vietnam: 3rd Floor, Thang Long A1 Building, Thon Bau, Thien Loc Commune, Hanoi - 0983 797 186 / 090 345 9186 / 090 5859 186
Southern Vietnam: 551/212 Le Van Khuong Street, Tan Thoi Hiep Ward, District 12, Ho Chi Minh City - 098 6784 186
Email: sales@icdvietnam.com.vn
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References
- Wikipedia, Polyethylene (classification by density, melting point, UHMWPE, PEX, 34% market share) - en.wikipedia.org
- ASTM D4649, Standard Guide for Selection and Use of Stretch Wrap Films - astm.org
