Important
Remember that you MUST click Calculate after each modification or group of modifications prior to seeing the corrected final values.
Calculated accuracy of current Javascript enabled browsers is generally 16 places.
Technical Information
This calculator requires the use of Javascript enabled and capable browsers. Though it does intensive math calculations, it is a close estimator and enables the user to approximate the amount of paint required for a given wall, based on parameters entered.
How Calculations Work
THIS IS A COMPLEX CALCULATOR! Pay close attention to the instructions and options. It calculates the square footage of surfaces requiring paint, less that area occupied by doors or windows.
Assumptions
- It assumes the average door is 21 square feet in surface and the average window is 16 square feet. If your doors and windows are smaller than that or larger than that, you may use fractions such as 1.5 or .8 in the doors or windows field.
- It assumes that application paint goes on at about 350 square feet per gallon and 330 square feet for base paint; you may change either or both if you wish. It also assumes walls are smooth but allows for standard texturing or heavy texturing. It takes into consideration spraying, which takes slightly more paint than the alternatives, brushing or rolling, either of which requires roughly the same quantity of paint but less than spraying.
- It considers one or two application coats and assumes no base coat. The algorithm for the base coat is slightly different based (no pun intended) on the different composition of base coat paint; it also allows for a different price.
About Measurements
NOTE: The square footage of the wall is based on the actual measurements. All other square footage reporting is CALCULATED based on the actual wall size and the perceived rate of paint coverage determined by coverage options selected.
If you wish to use a base coat of a different type of paint, check the base coat box.
About Painting Environment
If you are in an exceptionally arid or desert environment, creating a very dry condition 80 percent of the year, check the dry climate box.
Important Considerations
- This calculator does NOT take into consideration trim surfaces as being separate.
- Be aware that the wall square footage does NOT include other walls, unless those walls have the same measurement. You can then change the number of walls from 1 to however many there are.
- The paint-able square footage includes the number of identical walls designated, assuming that they are identical, less doors and windows, and has the selected options of coats and other increases or decreases in paint quantity on it. It is actually the amount of calculated square feet for all of the conditions and determines the amount of gallons required.
Please note:
This calculator is for basic estimations only. Please consult a professional before making a final decision.
