Here are a few useful formulas that will help you calculate how thick your liner should be to handle your refuse safely.

Mils and Microns
A mil is a unit of length in thousandths of an inch (for example, .001 = one thousandth of an inch or 1.0 mil) typically used to designate the thickness of linear low density liners.

A micron (also refered to as a mic) is a metric unit of measure and is equal to one thousandth of a millimeter. A mic is typically used to designate the thickness of high density products.

You can easily convert with the following formulas:

Converting Mils-to-Microns     Multiply the number of mils by 25.4

For example:   .75 mil x 25.4 = 19 microns

Converting Microns-to-Mils     Divide the number of microns by 25.4

For example:    14 microns / 25.4 = .55 mil

Determining Mil Thickness, Case Weight and Sizing

LLDPE net case weight     (W x L x Mil) / 15 = lbs. per 1000

For example:     24 x 23 x .4   /  15  =  14.7 lbs. / 1,000
 
HDPE net case weight      ( W x L x Mic )  /  25.4  /  14.7 = lbs. per 1,000

For example:     24 x 24 x 6 / 25.4 / 14.7 = 9.2 lbs. / 1,000)
 

Pounds to grams     Number of lbs. x 454
 
Ounces to grams     Number of ounces / 16 x 454

Calculating Average Gauge From a Single Bag
Gauge = bag weight (in grams) x 30.5 / width / length / density   (.92 for LL; .95 for HD)

Calculating Case Weight from the Weight of One Bag
Case weight (in lbs) = bag weight (in grams) x case count / 454