Ask the Expert Question-and-Answer Archive

by Ron Joseph

December, 2007

Calculating Thickness

Q: If I know the dry film amount in grams on a known sq. ft. substrate and I know the volume solids and density, how do I calculate the mil thickness?

A: You can calculate the film thickness from the algorithm:

Coverage (ft2) = 1604 x Gals x Fraction Volume Solids
                              Dry film thickness (mils)

Where 1604 is the coverage of 1 gallon of solids applied to a film thickness of 1 mil (= 0.001 inches)

Notice that density of the paint is not required for this calculation.

Therefore:

Dry film thickness (mils) = 1604 x Gals x Fraction Volume Solids
                                                       Coverage (ft2)

Gals = Weight (lbs)
         Density (lbs/gal)

Therefore, substituting for Gals:

Dry film thickness (mils) = 1604 x Weight (lbs) x Fraction Volume Solids
                                            Density (lbs/gal) x Coverage (ft2)

Since 1 lb = 453.6 grams

Dry film thickness (mils) = 1604 x 453.6 x Weight (grams) x Fraction Volume Solids
                                                 Density (lbs/gal) x Coverage (ft2)

Regards,

Ron Joseph