Mil to Micron, MM and Gauge Conversion Chart for Plastic Film
Mil, micron, millimeter and gauge are four ways of writing the same film thickness. The table converts every common packaging thickness from 0.5 to 10 mil, the second table handles stretch and shrink film gauge, and the third says what each thickness is actually used for with stocked examples.
The four thickness units and how they relate
Plastic film in North America is sold by the mil, which is one thousandth of an inch. The rest of the world uses microns (micrometers, µm), one thousandth of a millimeter. Stretch film and shrink film are quoted in gauge, which is mil multiplied by 100. The conversions are exact because they all trace back to the inch: 1 mil = 0.001 in = 0.0254 mm = 25.4 µm = 100 gauge.
Formulas: mil x 25.4 = microns. Microns / 25.4 = mil. Gauge / 100 = mil. Gauge / 4 = microns (close enough for film; exact is gauge x 0.254). mil x 0.0254 = mm.
Mil to micron, millimeter, inch and gauge: 0.5 to 10 mil
Mil is not millimeter. A 2 mil bag is 0.0508 mm, which is one twentieth of a millimeter. The confusion runs the other way too: a spec sheet that says 50 µm means roughly 2 mil, not 50 mil. The table covers every thickness that packaging is commonly sold in.
| Mil | Inches | Millimeters | Microns (µm) | Gauge |
|---|---|---|---|---|
| 0.5 | 0.0005 | 0.0127 | 12.7 | 50 |
| 0.6 | 0.0006 | 0.0152 | 15.2 | 60 |
| 0.7 | 0.0007 | 0.0178 | 17.8 | 70 |
| 0.75 | 0.0008 | 0.0190 | 19.0 | 75 |
| 0.8 | 0.0008 | 0.0203 | 20.3 | 80 |
| 0.9 | 0.0009 | 0.0229 | 22.9 | 90 |
| 1 | 0.0010 | 0.0254 | 25.4 | 100 |
| 1.1 | 0.0011 | 0.0279 | 27.9 | 110.00000000000001 |
| 1.25 | 0.0013 | 0.0318 | 31.8 | 125 |
| 1.5 | 0.0015 | 0.0381 | 38.1 | 150 |
| 1.75 | 0.0018 | 0.0444 | 44.4 | 175 |
| 2 | 0.0020 | 0.0508 | 50.8 | 200 |
| 2.25 | 0.0022 | 0.0571 | 57.1 | 225 |
| 2.5 | 0.0025 | 0.0635 | 63.5 | 250 |
| 3 | 0.0030 | 0.0762 | 76.2 | 300 |
| 3.5 | 0.0035 | 0.0889 | 88.9 | 350 |
| 4 | 0.0040 | 0.1016 | 101.6 | 400 |
| 4.5 | 0.0045 | 0.1143 | 114.3 | 450 |
| 5 | 0.0050 | 0.1270 | 127.0 | 500 |
| 6 | 0.0060 | 0.1524 | 152.4 | 600 |
| 7 | 0.0070 | 0.1778 | 177.8 | 700 |
| 8 | 0.0080 | 0.2032 | 203.2 | 800 |
| 10 | 0.0100 | 0.2540 | 254.0 | 1000 |
Stretch and shrink film gauge to mil and micron
Stretch film is labeled in gauge. 80 gauge is the standard hand wrap, 60 and 70 gauge are economy or pre-stretched, 90 to 120 gauge are for heavy or sharp loads. Pre-stretched film is thinner on the roll (often 38 to 47 gauge) because it has already been stretched at the factory and is rated by load performance rather than nominal thickness. Shrink film is quoted the same way; 60 and 75 gauge polyolefin are the common retail wraps. The stretch film gauge chart maps each gauge to a load weight.
| Gauge | Mil | Microns | Millimeters |
|---|---|---|---|
| 38 | 0.38 | 9.7 | 0.0097 |
| 47 | 0.47 | 11.9 | 0.0119 |
| 50 | 0.5 | 12.7 | 0.0127 |
| 60 | 0.6 | 15.2 | 0.0152 |
| 63 | 0.63 | 16.0 | 0.0160 |
| 70 | 0.7 | 17.8 | 0.0178 |
| 75 | 0.75 | 19.0 | 0.0190 |
| 80 | 0.8 | 20.3 | 0.0203 |
| 90 | 0.9 | 22.9 | 0.0229 |
| 100 | 1 | 25.4 | 0.0254 |
| 120 | 1.2 | 30.5 | 0.0305 |
| 150 | 1.5 | 38.1 | 0.0381 |
| 200 | 2 | 50.8 | 0.0508 |
What each thickness is used for
Thickness is a proxy for puncture resistance, stiffness and clarity. Doubling mil roughly doubles puncture resistance and also doubles material cost and weight per bag, so the right answer is the thinnest film that survives the contents and the trip. The examples link to products in each band that are stocked on this site.
| Thickness | Microns | Typical packaging use | Stocked examples |
|---|---|---|---|
| 0.5 to 0.8 mil | 13 to 20 | Garment bags, produce bags, light can liners, sandwich bags | 0.6 mil garment bags, 0.4 to 0.9 mil can liners |
| 1 mil | 25 | Light poly bags for dry goods, pallet top sheets, dust covers, light pallet covers | 1 mil poly sheeting, 1 mil pallet covers |
| 1.5 mil | 38 | Standard flat and gusseted poly bags, poly tubing, recycling liners | 1.5 mil poly bags, 1.5 mil poly tubing |
| 1.6 to 1.9 mil | 41 to 48 | Economy and standard acrylic carton sealing tape (the tape film plus adhesive) | 1.6 mil acrylic tape, 3M 371 at 1.9 mil |
| 2 mil | 51 | The default poly bag and reclosable bag thickness, 2 mil pallet covers, poly tubing | 2 mil reclosable bags, 2 mil flat poly bags |
| 2.2 to 2.5 mil | 56 to 64 | Heavy duty carton sealing tape, surface protection film | 3M 373 at 2.5 mil, carton sealing tape |
| 3 mil | 76 | UV amber bags, heavier reclosable bags, pallet covers for outdoor storage, barricade tape | 3 mil UV bags, 3 mil pallet covers |
| 3.1 mil | 79 | Static shielding bags for circuit boards | 3.1 mil static shielding bags |
| 4 mil | 102 | Heavy poly bags for parts and hardware, 4 mil sheeting, 4 mil poly tubing, machinery covers | 4 mil poly bags, 4 mil black sheeting |
| 4.9 to 6 mil | 124 to 152 | Masking tape, duct tape, vinyl safety tape, 6 mil heavy duty bags and sheeting | 4.9 to 6 mil masking tape, 6 mil reclosable bags |
| 7 to 8 mil | 178 to 203 | Reinforced water activated tape, filament tape, 8 mil heavy flat poly bags | 7 mil reinforced kraft tape, 8 mil flat poly bags |
| 10 mil and up | 254 and up | Gaffers tape, VHB bonding tape, anti-slip tape, floor marking tape | 11 mil gaffers tape, floor marking and anti-slip tape |
Decision rules
- Soft, light, no corners: 1 to 1.5 mil. Apparel, paper goods, food service items.
- Everyday parts and retail goods: 2 mil. This is the default for a reason; it seals well on an impulse sealer and resists tearing on a pick line.
- Metal parts, hardware, anything with an edge: 4 mil. Below that, corners poke through during handling.
- Sharp, heavy, or stored outdoors: 6 mil and up. Castings, fasteners in bulk, long-term storage under UV.
- Electronics: thickness is secondary to the material. Use 3.1 mil static shielding or pink anti-static film rather than a thicker clear bag. The anti-static vs regular bag guide covers the difference.
- Carton sealing tape: 1.6 to 1.9 mil for light single wall cartons, 2.2 to 2.5 mil for heavier or recycled-content board, 3 mil and above for double wall or cold storage. See the tape mil thickness guide.
For the common head-to-head questions, the 2 vs 4 vs 6 mil poly bag comparison and the 6 mil vs 4 mil plastic sheeting pages go deeper on a single choice.
Reference values: 1 inch = 25.4 mm by definition (international inch, 1959). Gauge as used for plastic film is defined as 100 gauge = 1 mil; it is unrelated to wire gauge or sheet metal gauge.
Shop poly bags by milStretch film
Frequently asked questions
How many microns is 1 mil?
25.4 microns. One mil is one thousandth of an inch, and an inch is 25.4 millimeters, so a mil is 25.4 micrometers exactly.
Is 6 mil thicker than 4 mil?
Yes. 6 mil is 0.006 inch (152 microns) and 4 mil is 0.004 inch (102 microns), so 6 mil is 50 percent thicker. Larger mil numbers always mean thicker film.
What is 2 mil in mm?
0.0508 mm, a little over one twentieth of a millimeter. 2 mil is also 50.8 microns and 200 gauge.
How do I convert gauge to mil?
Divide gauge by 100. 80 gauge stretch film is 0.8 mil, or about 20 microns. To go from gauge to microns directly, multiply by 0.254.
What thickness is 100 micron plastic in mil?
About 4 mil. 100 divided by 25.4 is 3.94, and film sold as 4 mil in the US is the same product as 100 micron film sold elsewhere.