Plastic Gauge to Microns Converter
Convert polythene and plastic film thickness between gauge, microns, mil, millimetres and inches in one step, and see the nearest common gauge.
Convert Film Thickness
Enter a thickness, choose the unit you have, and the converter shows the same thickness in every other unit. Use it for polythene sheeting, bags, damp proof membranes and shrink film.
Gauge to Microns Converter
Two-way conversion between five thickness units.
Understanding Plastic Gauge
How gauge, mil and microns relate
What Gauge Means
In plastic film, gauge measures thickness. 100 gauge equals one thousandth of an inch, so a higher gauge means a thicker film.
The Formula
Microns = gauge × 0.254. To go back, divide microns by 0.254. For example, 1000 gauge × 0.254 = 254 microns.
Mil vs Micron
A mil is 0.001 inch or 25.4 microns. US suppliers quote mil, while UK and European suppliers usually quote microns or gauge.
Not Sheet Metal Gauge
Sheet metal and wire gauges use different scales where a higher number often means thinner. This converter is for plastic film only.
Gauge to Microns Chart
Common polythene gauges with their thickness in microns, mil and millimetres, and typical uses.
| Gauge | Microns | Mil | Millimetres | Commonly Used For |
|---|---|---|---|---|
| 25.4 µm | 1 mil | 0.025 mm | Light wrapping, thin bags | |
| 38.1 µm | 1.5 mil | 0.038 mm | Light bags, dust covers | |
| 50.8 µm | 2 mil | 0.051 mm | General purpose bags and covers | |
| 63.5 µm | 2.5 mil | 0.064 mm | Stronger bags, dust sheets | |
| 76.2 µm | 3 mil | 0.076 mm | Heavy-duty bags and sheeting | |
| 101.6 µm | 4 mil | 0.102 mm | Heavy-duty bags, protective covers | |
| 127 µm | 5 mil | 0.127 mm | Greenhouse insulation, builders’ sheeting | |
| 152.4 µm | 6 mil | 0.152 mm | Heavy sheeting, ground cover | |
| 182.9 µm | 7.2 mil | 0.183 mm | Polytunnel and greenhouse covers | |
| 203.2 µm | 8 mil | 0.203 mm | Heavy-duty sheeting, pond liners | |
| 254 µm | 10 mil | 0.254 mm | Damp proof membrane (DPM), builders’ sheeting | |
| 304.8 µm | 12 mil | 0.305 mm | Heavy-duty DPM, temporary protection |
Gauge to Microns FAQ
Answers to the most common questions about plastic film thickness.
Multiply the gauge by 0.254. For example, 250 gauge × 0.254 = 63.5 microns. This works because 100 gauge equals 1 mil, and 1 mil equals 25.4 microns.
1000 gauge polythene is 254 microns. It is usually sold as 250 micron sheeting and is commonly used as a damp proof membrane (DPM).
A mil is one thousandth of an inch (0.001 in, or 25.4 microns). In plastic film, 100 gauge equals 1 mil, so 400 gauge is 4 mil.
No. Plastic film gauge is a simple measure of thickness where 100 gauge equals 0.001 inch. Sheet metal and wire gauge systems use different scales, and a higher number there usually means a thinner material.
Divide the microns by 0.254, or multiply by about 3.937. For example, 100 microns ÷ 0.254 = 393.7 gauge, which is usually sold as 400 gauge.