ContractorHandbook

How Much Paint for a 1200 Square Foot House?

Paint needed

17 gallons

A 1,200 sq ft house, interior walls taken as 2.8 times the floor area, ten doors, twelve windows, two coats.

It does not stop at a number.

When the figures look right, the paint material list downloads as a real PDF with your business details on it, built inside your own browser. Nothing you type is uploaded anywhere.

doorwindowwindowheightperimeter of the room, ftnet wall area x coats / coverage per gallon = gallons
A room painted is its perimeter multiplied by its height, laid out flat, with the doors and windows taken out. Multiply by the number of coats before dividing by the coverage on the can, because two coats is two full areas of paint.

How that number is worked out

These are the figures this page was built with and every line the calculator produces from them. Change anything above and all of it moves.

  • Room perimeter, add all walls420 ft
  • Wall height8 ft
  • Doors10
  • Windows12
  • Coats2
  • Coverage per gallon350 sq ft

Paint needed17 gallons

Gross wall area3,360 sq ft
Less doors and windows-390 sq ft
Net wall area2,970 sq ft
Area over 2 coats5,940 sq ft
Gallons, exact16.97
Buy17 gallonsor 4 five gallon pail

The material list this produces

Paint, gallons17
Primer, gallons (if bare or color change)9
Painter's tape, rolls7

Coats compared

Coats is the input people get wrong, usually by hoping. Same room, one coat to three.

CoatsPaint needed
1 coat8.5 gallons
2 coats17 gallons
3 coats25.5 gallons

What else matters here

A whole house is a different question from a room, because the wall area is not something you can measure with a tape in five minutes. The working rule is that interior wall area runs around two and a half to three times the floor area once every room division, hallway and closet is counted, and this page uses 2.8.

On 1,200 square feet that is 3,360 square feet of wall gross, 2,970 after ten doors and twelve windows, and about 17 gallons over two coats. If your house is open plan it will be less, because open plan means fewer internal walls; if it is chopped into small rooms it will be more.

Buy it in five gallon pails rather than gallons. Four pails covers this with a little spare, costs meaningfully less than seventeen single gallons, and removes any question of color variation between containers.

What this calculator assumes

  • A door is taken as 21 sq ft and a window as 15 sq ft. Deducting them matters on a small room and barely moves a big one.
  • 350 sq ft per gallon is the usual figure on a smooth primed wall. Bare drywall, textured walls and deep color changes all drink more, so drop it to 300 if any of those apply.
  • Ceilings and trim are not included. Run the ceiling as its own area.

Questions people ask

How much paint for a 1200 square foot house?

About 17 gallons for two coats on the interior walls, taking wall area as roughly 2.8 times the floor area.

How do I work out the wall area of a whole house?

Multiply the floor area by about 2.8 as a starting point. Open plan houses come in lower, houses divided into many small rooms come in higher.

Is that figure for walls only?

Yes. Ceilings, trim, doors and closets are all separate, and ceilings alone will add roughly another four gallons on a house this size.

Different numbers?

The paint calculator takes any dimensions you like and hands back the same list.

Other common sizes