How do I calculate the square footage of a room

Take the width times the length and multiply them, this will give you the sq. footage, now add the sq. footage of all the walls and ceiling? (floor?) and add them up. Now do the same with the windows and doors and subtract this number from the sq. footage of the walls ,this will give you the net wall surface.The floor sq. footage is just the width times the length.

Square footage for a 12 x 14 bedroom with an 8 ft ceiling.

Ceiling: multiply 12 x 14 = 168 sq.
Walls: add 12 + 14 = 26 x 2 = 52 which is the perimeter of the room.
Now times 52 x 8 (the perimeter x the height of the ceiling) this gives you 416 sq. of wall space.

Add (walls 416) + (ceiling 168) = 584 total sq.

In the average size bedroom, I don't usually subtract sq for small windows or one door.
You will get 400 sq per gallon.

A room this size with a two coat finish, you will need 1 gallon of paint for the ceiling and if you are going with a different color for the walls, you will need 2 gallons of paint for the walls.

You will have touch up paint left over!

Wow! You guys are good! I had no idea the color of paint made a difference! Lol!

I did however know multiply width x length for sq. ft... Oh, and I did stay in a Holiday Inn Express last night! Lol! I win! :p :D

Wow! You guys are good! I had no idea the color of paint made a difference! lol!

I did however know multiply width x length for sq. ft......Oh, and I did stay in a Holiday Inn Express last night! lol! I win! :p :D
Color of paint DOES NOT make a difference. If you are painting a bedroom 12x14 most people paint the ceiling white and the walls a different color. So if there is 1/2 a gallon left from the wall paint, you won't be using it for the ceiling. Keep it for touch up!

Get it now?:rolleyes:

Allll'Rightey then! Gotcha! :)

I just misread your post... its late, or early depending on how you look at it!

I edited my first post so it was easier to understand. Its getting late over here in NJ...
BTW - I am a painting contractor...