How many square feet does one gallon of paint cover?

Answer 1

gallonsquare feet
Other websites say a gallon will cover 400-450 square feet of smooth surface. If you've got a rough textured surface or surfaces which need 2 coats of paint, a gallon will cover about 200 square feet.


The above answer may be a general rule of thumb. However so many people on here are passing themselves off as professionals with out actually knowing or at least explaining the real answer to this question.

Technically this question can not be answered with out more information. First and foremost the % of solids by volume must be known. Ultimately that number gives you actual amount of product that will be left behind on your wall when the paint dries.

Texture simply adds to the area of the surface your are painting. The smoother a wall the less area you have to paint. If the wall is textured the height of the peaks and the lows of the valleys increase the area within the same square foot.

Example: If you imagine two cities joined by a flat road 100km apart and you are driving 100km/hr it is going to take 1 hour to drive from one city to the other. Now imagine the same two cities joined by a road but this time the road has a mountain between the cities. The horizontal distance is still 100km apart but now you must go up the mountain then back down the mountain to reach your destination. Obviously if driving at 100km/hr you are going to take longer to make this trip. The reason it takes longer is because it is farther going up the mountain then back down to reach your destination. A rough wall surface acts like a mountain !

Now to answer the above question lets assume that you have 100% solids by volume paint. That gallon of paint is going to spread out at 1604sq' at 1 mil thick. Don't ask how I know this but it is a fact. 100% solids by volume paint no matter the type will always spread at this number (1604sq' per mil). Now if you have a substrate with 400sq' to paint and use 100% solids paint then it is going to take :

400sq' / 1604sq' per mil = .249 gal at 1 mil thick

Now if you need the paint to be 4 mil thick to provide the coverage and protection then the math is as follows:

1604sq' per mil per gal / 4mil required = 401sq' per gal

400sq' / 401 sq per gal at 4 mil thick = .9975 gals is required

Now lets say that your paint is only 50% solids by volume then the math would be as follows:

1604sq' per gal at 1 mil x 50% solids per gal = 802 sq' at 1 mil

802 sq' per mil per gal / 4mil required = 200.5 sq' per gal

400sq' / 200.5 sq' per gal at 4 mil thick = 1.995 gals is required

Now all the above calculations are assuming 100% transfer of product (no waste) as that is unlikely to ever take place you must accommodate for waste. use a percentage of expected wast and apply that to the figure you end up with to increase the amount required.

Now this calculation system will work for any type of paint at any % solids by volume. But without knowing the % solids by volume of the product you are using any number that you come up with will simply be a guess.

So now you know !

Use the information wisely ! :-)

Answer 2

That really does depend on what film thickness you want and also the volume solids of the paint. Let us assume the volume solids is 100% (it wont be trust me). Let us assume a huge thickness of 1/10 inch spread evenly over the square foot

Then 1ft x 1ft x 1/12 1/10 gives the cubic footage and there are 7.48 US gallons per square foot (I could derive this but look it up) then 1ft x 1ft x 1/12 x 1/10 x 7.48 means it will take 0.062333---- gallons to cover 1 square foot at 1/10 inch thickness at 100% volume solids. To convert to a coverage rate i.e square feet per gallon, take the reciprocal = 1/0.062333--- = 16.0427 square feet.

Now for a more normal 10 mils or 1/100 inch it would be 10 times the coverage i.e. approximately 160 square feet per gallon.

Another assumption is also being made - the substrate absorbs ZERO of the paint - which is not true as for good adhesion some is always absorbed especially with good surface preparation and roughness (hence surface area). If you had a latex paint at say 50% volume solids then to get the same dry film thickness you would only get 80 square feet per gallon and so on

Answer 3

Depending on the texture of the surface being painted, anywhere from 250, for a very rough textured surface, to 375 for a smooth wall. Theoretical coverage of a gallon of paint, spread at the proper 4 mil thickness is 400 ft with no waste.

Solid stains go on thinner, so they will go farther.

Answer 4

The answer depends on several factors. These include:

• the paint
• the quality - especially the porosity - of the surface to be painted
• the preparation of the surface to be painted.
  

Answer 5

depends on what your putting it on, hardwood goes farther than pine etc...it will be on the bucket

Answer 6

For one coat, about 300 sq ft for smooth surface, about 150sq ft if surface is rough like a plastered ceiling

Answer 7

The answer will vary, depending on how thick the paint is spread. This, in turn, depends on the type of paint, and on how it is applied.

Answer 8

it depends on how rough the surface is; for smooth surface about 300 square feet; for rough ceilings 150 square feet

Answer 9

A gallon paint covers 350 to 400 sq.ft

Answer 10

400 sq. ft.