How much paint do i need ,you can google examples of this calculator

Painter Forum's Paint Quantity Calculator 

Round all measurements up to the nearest 1/2 ft. and enter all measurements in decimals. for example 12 ft. and 3 inches should be entered as 12.5
Do not deduct for windows and doors, this will account for setup and cleanup paint waste 

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INTERIOR SMOOTH WALL PAINTING :

1. Measure the height of the wall from top of baseboard to ceiling, or to ceiling molding.


Enter the number of feet


2. Measure the distance around the room, this will be the total length of all four walls.


Enter the number of feet

    Gallons for one coat of paint