Handyman Paint Calculator

It’s a simple tool that helps you estimate how much paint you’ll need for your project based on wall(s) dimensions, number of doors, number of windows, ceiling dimensions, and paint coverage.

You enter the wall’s width, and height along with the number of doors, and their width and height, number of windows, and their width and height,. The calculator then estimates the total square footage to be painted and the gallons of paint required.

Yes. By entering the number and approximate sizes of doors and windows, it deducts those areas from the total wall area to be painted.

The calculator provides a close estimate based on average paint coverage (usually 400 sq. ft. per gallon). Actual usage may vary depending on paint type, surface texture, and application method.

Formula and Calculation :

For wall(s):

Total area of wall(s) = Wall Height x Wall Width
Total area of door(s) = number of doors x door height x door width
Total area of widows(s) = number of windows x window height x window width

Recommended account of paint required = (Total area of wall(s)- (Total area of door(s)+Total area of window(s))/paint coverage per Gallon

(paint coverage per Gallon usually 400 per gallon )*

Example:

wall height = 12 ft
wall width = 60 ft
number of door(s) = 1
door height = 7 ft
door width = 2 ft
Number of window(s) = 1
Window height = 3 ft
Window width = 2 ft
(paint coverage per Gallon: 400)*

Recommended amount of paint required for wall(s) = ((60 X 12)- ((1 X 7 X 2 )+(1 X 3 X 2))/400

= (720 – (14 + 6))/400

= 1.75 ≈ 1.8 Gallon per Coat

For Ceiling:

Total area of ceiling = length x width

Recommended amount of paint required for ceiling = (15 X 12 )/400 = 0.45 ≈ 0.5 Gallon per Coat