How To Calculate Paint Needed

How Much Paint Is Needed For Walls

Estimating the Amount Of Paint Needed For Interior Surfaces
  • Start by adding up the length of all the walls to be painted, from end to end.
  • Then multiply that number by the height of the walls, from floor to ceiling. That will give you the square footage of the room to be painted.
  • Finally, divide your total number by the approximate coverage of one gallon of paint . This gives you how many gallons of paint you need for one coat of paint on the walls.

Pro2Pro Tip: Dont forget the second coat! The rule of thumb is to apply two coats of paint on walls and one on the ceiling, but individual situations vary.

How Much Primer Do I Need For My Interior Painting Project

Primer is used to help new paint adhere to a wall better, commonly used on walls that are porous, unpainted, making a dramatic color switch, or when covering up stains. When one uses primer, it doesnt affect how much paint one will need, as applying two coats on top of the primer is still recommended.

However, the math is slightly different if one is trying to calculate how much primer to buy. Primer cans hold less volume than paint cans, covering only 200-300 square feet compared to a paint cans 400. Therefore, we recommend replacing 400 with 200 in the equation above to get an appropriate amount.

How Much Does It Cost To Paint A Room 12×12

The cost of painting a room is determined by how much paint you need as well as the cost of each gallon of paint. First, we need to calculate. the square footage of the room. This room is 12 x 12 with 8 foot ceilings. This room has 384 square feet . If we know that we will use around 2 gallons for two coats in this room. If the average cost of paint is between $15-$60 a gallon, the cost will be between $30- $120 for the whole room, depending on the kind of paint we choose.

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Paint Calculator For Ceilings

Calculating how much paint you need for the ceiling is a lot less complicated than doing it for the walls.

To start off, you need to multiply the width of your ceiling into its length.

For instance, keeping the above measurements in mind, the paintable area size of an 11 x 15 ceiling will be 165 sq ft.

You will then have to divide this number by 350 to calculate how many gallons of paint you should purchase.

165 ÷ 350 = 0.4

In this case, you should purchase two quarts of paint for your ceiling. However, if you want to do another coat, buy 1 gallon of paint instead.

1 gallon = 4 quarts

How Much Paint Do I Need For My Walls

Before you calculate how much paint you need. You need to get the rooms ...

To determine how much paint one will need to cover their walls, we recommend doing the following.

Step 1: Measure the length of the walls that need to be painted, from end to end. This will give you the perimeter of the room.

Step 2: Measure the height of all the walls that need to be painted.

Step 3: Multiple the perimeter by the height. This will give you the square footage of the room.

Step 3.5 : Multiple this number by however many coats you want to paint. Typically, two coats are recommended.

Step 4: Divide the square footage by 400. 400 is the approximate coverage a single can of paint will provide for one coat.

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Interior Painting How To Calculate How Much Is Needed

One of the most exciting parts of buying or personalizing a house is painting the interior to make your living space a true reflection of your personality and values.

If you decide to paint indoors, its important to calculate the amount of paint youll need, as well as some helpful tips to get you started.

Size Of The Room Or Surface

The most important factor in determining how much paint you need is the size of your room or the surface you are painting.

Painting the Walls

  • First, measure the distance or perimeter around the room in total feet.
  • Next, multiply this number by the height of the walls up to the ceiling.
  • Then, calculate the area of the windows and doors and subtract this from the total square footage to get your final number.
  • Example

  • We are beginning with a room that measures 10 feet on two walls and 12 feet on two walls. If we add 10 + 12 = 22 and then multiply this total number by 2, we get 44 feet.
  • Next, we multiply this number by the height of the walls up to the ceiling which is 8 feet high. Therefore, our numbers look like this 44 ft x 8 ft = 352 square feet.
  • Then, you need to subtract the square footage from the number of doors and windows you have in the room. We will calculate one door and two windows in this room. The square footage of our door is 21 sq. feet and the two windows are each 15 square feet each . We add these together and then subtract 51 square feet from our total square footage. 352 sq. ft.- 51 sq. ft. = 301 square feet.
  • Therefore, since a gallon of paint covers around 300-400 square feet, you need one gallon of paint for one coat in this room. If you are painting more than one room the same color, calculate all the square footage together.
  • Painting the Ceiling

    Calculate the total square footage of the ceiling by measuring the length x width and multiplying it by 2.

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    How Much Paint Do I Need

    Need to know how much paint to buy? A little math can save you a lot of time when it comes to interior painting.

    Anyone with their first interior home painting project has stood in the paint aisle wondering how many cans they need to bring home.

    To keep your colors matching and avoid return trips to the store, do some calculations ahead of time:

    Other Important Factors To Consider When Calculating The Amount Of Paint Required Are:

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    • If you are painting over existing dark colours, and require the finish to be in a pastel colour, it would be necessary to allow for 3 coats instead of 2. Applying a base colour of white could also be considered prior to the application of the 2 coats of the required colour.
    • If you are looking to decorate in colours from the deep red or deep yellow spectrum, you may need to consider allowing for 1-2 more coats to achieve full opacity. This is due to the pigments being used will need to mixed into clearer bases to achieve the required deep colour.

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    How Much Paint Is Needed For Trim

    A rooms baseboards, windows, doors, and crown molding are often painted in a different finish or color than the walls and ceiling, so you can calculate your trim paint needs separately.

    • Add up the length of all the trim to be painted, then add up the width of all the trim.
    • Multiply length x width to get the square footage of trim to be painted.
    • Divide the total by 400 to get the number of gallons of paint youll need for one coat. Youll likely need less than a gallon for a standard room, so consider buying trim paint in a quart or two.

    Pro2Pro Tip: If youre painting the interior trim between windowpanes, theyre approximately 7.5 square feet of paintable space.

    Determine Your Paint Needs With This Simple Calculator And Room Examples

    Emily Manchester is the General Manager of Better Homes & Gardens. She has been working in the home space for six years, and in digital content for eight years. Previously, Emily led all editorial and strategy decisions for The Spruce and MyDomaine, two other home brands under the Dotdash Meredith umbrella.

    The Spruce / Margot Cavin

    This paint coverage calculator makes calculating the amount of paint you’ll need for your project a nearly automatic task. Your own role in the process involves just a few elements:

    • Measuring the height and width of each wall to be painted.
    • Logging in the number of windows and doors in the space
    • Pressing the “Calculate” button.

    If that doesn’t sound easy enough, let’s go through each step individually.

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    Time To Build Your Paint Job Estimate

    • Use a branded estimate form or letterheadyou can use a customizable painting estimate template or estimating software.
    • Clearly outline the entire scope of the project, listing out all the jobs you will performfrom prep work to cleanup and customer review.
    • Deliver your painting estimate as promptly as possible after your site visit and offer to answer any customer questions.

    Bulky Figure: How Much Paint Do I Need To Paint A Room

    How Much Paint Do I Need?

    It depends on the dimensions of the room. To find out how much paint you need, measure the dimensions of the room. Then, use our handy paint calculator to find out how many litres of paints youll need for coverage.

    If youre only looking for a rough idea of how much paint youll need at the moment, here are some figures from common room sizes we have painted in the UK.

    Small children bedroom.

    For any bedroom that will fit a single bed, small wardrobe and a table and that have a medium-sized window and a regular door, youll need 4 litres of paint for the walls in 2 coats and 2 to paint the ceiling.

    Medium size master bedroom

    For a medium-sized master bedroom that fits a double or super king-sized bed and has large windows, you will need 5 litres of paint to paint the walls in 2 coats and 2.5-3 to paint a ceiling.

    Large family sitting room

    For a large family sitting room, you will probably need 6 litres of paint to paint the walls in 2 coats and 4-5 to paint a ceiling.

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    Be Thorough In Your Scope

    Avoid relying on a potential customers estimated square footage of the job. Even if theyre giving you accurate numbers, this is a great opportunity to show off your careful professionalism and build invaluable trust by using your tape or laser measure and calculating it yourself. Bring your foreman or most experienced painter with you when you do your site inspection, as they will be able to help spot any potential red flags that may need extra attention or repairs, such as wall damage or trim that needs to be replaced. Once you have measurements, you can enter them into a paint job cost estimator to determine how much paint you need to buy . In addition to paint, be sure to add other essential supplies to your estimate using our Materials Checklist in the blue box.

    How To Calculate Costs

    Measure the room. In order to work out how much the painting project will cost you you will firstly need to know the area of the surfaces you intend to paint. This is a relatively simple task, all it needs is the ability to keep track of where you are and not miss anything. The equipment items you need are a retractable tape measure, a pencil and a pad of note paper.

    First task is to roughly sketch the outline of the room, one per page. Dont forget to include all the corners, positions of the doors and positions of each window.

    Now move around the room measuring the length of each wall and transferring the measurement onto the paper. Remember that this will be an estimated area so the dimensions do not have to be exact. If necessary you can overestimate the dimensions to the nearest whole number to make the calculations easy.

    Next job is to measure the height of the room from ceiling down to the top of the skirting board . Once again this measurement is an overestimate.

    Primer. To adhere to the bare wood surface and give the overlaying paint something to hold on to.

    Undercoat. This is a preparatory oil based coat designed to cover the underlying surfaces but allowing the top coat to adhere. Depending on how good the undercoat is at covering you may have to give two coats.

    Top coat. This is usually a gloss, silk, satin or matte finish. It is the top coat and provides the hardwearing shell protecting the underlying surface.

    Other problems

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    How This Paint Calculator Works

    This paint calculator helps you work out the minimum litres of paint you need per project, so you dont buy too much. The calculation is based on 10m² per litre of paint which is a pretty standard measurement, but some paints can vary. You just need to enter the dimensions of the space youre painting and a little more info, and you get a precise amount. You can even take off the square metres of the areas you dont want to paint too, things like windows and skirting boards, for example. Once you have measured the room and taken away all of the areas you dont want to paint, youll know the amount of paint to buy.

    Using The Paint Calculator

    How to Estimate The Amount of Paint To Paint The Exterior Of A Home

    The paint calculator is useful if you’re planning an interior or exterior home painting project. It automates calculations you could make yourself using fairly basic math skills. The calculator makes several basic assumptions in its computations:

    • One gallon of paint is assumed to cover approximately 350 square feet.
    • A standard door accounts for approximately 20 square feet.
    • An average window accounts for approximately 15 square feet.

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    How The Calculator Works: Examples

    Using the calculator is simply a matter of entering the length and height of the walls to be painted, then entering the number of windows and doors that interrupt the wall areas. All mathematical computations occur invisibly to produce a fairly accurate estimate of how much paint you’ll need.

    For example, let’s imagine you have a 12 x 12 room with standard 8-foot-high ceilings. Using the calculator works like this:

  • Pick a rooms shape .
  • Enter the length and height of each wall, individually .
  • Enter the number of windows and doors that interrupt the wall expanses .
  • Hit the “Calculate” button.
  • Automatically, the paint calculator gives you an estimate of 2 gallons of paint for applying two coats to a 12 x 12 room with 8-foot ceilings with two windows, 1 door, where you have no intention of painting the ceiling.

    Here’s another example: You have a shed or garage with exterior walls that are 25 feet long and 10 feet tall, for a total of 1,000 square feet. Because the existing walls are weathered and in poor shape, they’re likely to absorb a lot of paint and you estimate that three coats will be necessary. There are three windows and one door in your shed or garage. If you enter all these values into the paint calculator, you are given an estimate of 9 gallons to paint your structure.

    Of course, you could do these calculations by hand. But why bother, when this convenient app does the work for you?

    How Much Paint Do I Need For One Wall

    The amount of paint you need depends on the size of the wall. For example if you wall is 12 wide and 9 feet high, multiply these numbers together to determine the square footage of the entire wall. This would look like this: 12 x 9 = 108 square feet. Therefore, you will need just one gallon for a wall of this size for one coat or two coats of paint.

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    How Much Primer Do I Need

    Applying primer first helps the paint adhere properly to porous or unpainted surfaces like new drywall, allows for even paint application, and covers up stains. If youre making a dramatic color switch, a tinted primer in a shade similar to your paint makes coverage easier.

    Primer only covers 200-300 sq. ft. per gallon, so youll need slightly more primer than paint. Take your earlier total area and divide that number by 300 to get the minimum gallons of primer youll need for one coat.

    How Many Gallons Of Paint Do I Need

    Paint Calculator

    The number of gallons you need is dependent on the square footage of your room. Each gallon of paint will cover between 350 and 400 square feet. If you calculate that your room is 486 square feet, you will need 2-3 gallons depending on how many coats of paint you will need. The number of coats of paint is dependent on the actual paint colors, the surface types, and the application method you will use.

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    Calculating How Much Paint You Need

    In order to calculate how much paint you need to paint a room, house, or an exterior surface, you need to either know the measurements by plan, or have a long measurement tape ready before you can use this paint calculator. If you are painting an interior surface, you need to know the room’s width, length and height. Rooms with non-rectangular layout can be approximated to rectangles. If you need to paint a ceiling or external wall, switch to “External” in the calculator and just enter the total width and height of the wall .

    Usually the room or exterior will have openings for windows and doors which need to be excluded from the total surface area. Accurate measurement of the windows is important, especially if there are many of them. Our tool only supports one set of window dimensions, so if you have a room with multiple windows of highly different dimensions, you’d need to use the average. In this how much paint do I need calculator door dimensions are assumed to be close to construction standards .

    The other important thing to consider is the paint coverage efficiency : how many square meters or square feet you can cover with a litre or gallon of the paint. Manufacturers usually provide this information on the product label. Different paints and primers have different coverage capacity so make sure you use the right number as input. You’d want to allow for a lower efficiency in case the surface is not smooth. More coarse surfaces require more paint to cover.


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