Ask the Expert Question-and-Answer Archive

by Ron Joseph

October, 2003

Calculating Paint Coverage

Q. How do I calculate the amount of paint in gallons necessary to cover a part if I know, the amount of mills to apply and the sq ft of the part?

A: It is very easy to calculate theoretical paint coverage. The equation is as follows:

Where 1,604 is the number of sq. ft. that a solid gallon will cover at a thickness of 1.0 mils.

Example:
What is the coverage for 1 gallon of paint with 52% volume solids which is applied by spray with an approximate transfer efficiency of 30%? The dry film thickness of the applied coating is 1.5 mils.

Coverage (ft2) = 167 ft2.

You can usually get the volume solids of the coating from a technical data sheet, but you must guess at the transfer efficiency.

By manipulating the equation you can now figure out the number of gallons required to do a job if you have the remainder of the information.