Painting is one of the most important jobs to refurbish and redecorate our house for a more beautiful and refreshing look! However, before painting, have you calculated the required amount of paint for the needed area? If you are having difficulties in estimating the exact amount of paint to cover any surface, this article is for you! We will be pleased to help you on what you need!

how much room paint and exterior paintIt will deal with these problems:

  • How much area (in square feet) can a gallon of paint cover?
  • How can you estimate how much room paint and exterior paint you need?
  • What are basic tools for a normal pain project?

And other tricks that help you save paint for your house! Let’s begin!

How Much Area In Square Feet Can A Gallon Of Paint Cover?

Coverage Of Paint Per Gallon

Let’s answer this simple question first: “Using a gallon of paint, how much area can you paint?” Of course, the below results are just estimated coverage amounts. The actual amounts, in fact, can vary depending on application method or type and brand of paint. So, in general, one gallon of paint can cover approximately 350 – 400 square feet (32 – 37 square meters), which is equivalent to a small room like a bathroom or a kitchen.

So, what about two gallons, three gallons, four gallons of paint?. Here’s your bonus information:

Two gallons of paint can cover up 700 – 800 square feet ( approximately 65 – 74 square meters), which is equivalent to a room with an average size. Three gallons of paint can cover up 1000 – 1200 square feet (approximately 92 – 110 square meters), which means the area of a large room or two average sized rooms combined.

If you are going to paint a room with a dome, you can consider using three gallons. Four gallons of paint can cover up 1400 – 1600 square feet (approximately 130 – 148 square meters), which means you can paint several average rooms. If you have to paint some large rooms, four gallons will be a good choice.“How much of the area can 5 gallons of paint cover?” Wow, that is a massive amount of paint. You need to consider using them when the surface you want to paint is vast, or you are going to paint two or three coats.

Coverage Of Paint Per Gallon

What Are The Tips That You Need To Consider?

I’ll give you some useful tips in case you need them:

  • You may need a little bit more than a gallon if the walls are porous, drywall, rough, textured or previously unpainted, because they will absorb more of the paint.
  • If your color change is subtle, or your house has many spots which cannot be painted on such as window panes, less paint may be required.
  • To determine the number of coats of paint required, you can try to examine the surface you are going to paint. Then you decide whether to paint one coat or more than one coat.
  • If the walls are unfinished, heavily patched and you want to change from a light and bright color to a deep and dark one, the advice is applying two coats of paint or even a tinted primer.

Of course, the higher-quality and expensive paints generally will be more effective and long-lasting than cheaper ones. The reason is that cheaper paints often have less resin, which is the main component holding colors together.

What Are The Tips That You Need To Consider?

See also: best indoor paint sprayer

How Can You Estimate How Much Room Paint You Need?

What Is The Basic Formula To Estimate?

That’s basically the theory that you should remember for better use. Estimating the amount of paint you will use is very important before painting your house, wall, ceiling, door because it will save you tons of money when doing it correctly. Buying enough and sufficient amount of paint is art itself and will be very useful.

Here is the solution! You can take some simple calculations below to figure out how much paint to buy. First, add the length of all the walls in the room together. Then, multiply that number by the height of the room, from the floor to the ceiling. Importantly, you have to determine only how much of that area allows painting. Remember to subtract the area of any large door and windows. You are not going to use that paint for those windows, aren’t you?

So, you have a number close to the actual area you have to paint. Now move on to the last step. You still remember the paint coverage per gallon is 350 square-foot, right? Divide the needed painting wall area you’ve just calculated by 350 to find the number of gallons of paint you need. You can round it to the nearest foot if you want. It is like sitting in a math class again, isn’t it? Here is the simple example to illustrate this formula.

What Is The Basic Formula To Estimate?


Can you apply the calculations for determining how much paint you need for a room with the width of 15 feet and the length of 22 feet? It is 8 feet tall and has one 20-square-feet door and two 15-square-feet windows. If you want to paint the ceiling, Use the above formula to estimate the amount of ceiling paint you will use.

Step 1: Multiply the length by the width of the ceiling to find its area.
15 × 22 = 330 square feet

Step 2: Divide the result you have just found by the paint coverage per gallon (350 square feet). That is the number of gallons of paint you need to cover the ceiling.
330 ÷ 350 = ~ 0.9

In conclusion, you need 1 gallon of paint to cover the ceiling for a single coat. Double the result if you want to use two coats of paint. If you want to paint the walls, Use the above formula to estimate the amount of wall paint you will use.

Step 1: Add the length of the walls together.
(15 + 22) x 2 = 74 feet

Step 2: Multiply that number by the height of the wall. So now you have the total area of the wall.
74 × 8 = 592 square feet

Step 3: Calculate the area of the door and the two windows.
20 + 15 x 2 = 50 square feet

Step 4: Subtract the area of the door and two windows from the total area of the wall to figure out the actual area of the wall you are going to paint.
592 – 50 = 542 square feet

Step 5: Divide the result you have just found by the paint coverage per gallon (350 square feet). Now you have the number of gallons you will need to paint the walls of this room.
542 ÷ 350 ~ 1.5

In conclusion, you need 1 gallon and a half of paint to cover all the walls of this room for a single coat.In case, you have to estimate the amount of paint to cover a, door, window or woodwork, you only need to do similar steps


Here are some noteworthy points you have to consider when you round the uneven numbers of gallons of paint.

  • If the remainder is less than .5, purchasing a couple of quarts of paint with the gallons will be a suitable choice.
  • If the remainder is more than .5, I suggest you should buy an extra gallon. Don’t worry because you can use it for another purpose.

So, that is the guideline you can follow whenever you need specific calculations for the surface you want to paint. It seems that estimating how much paint you would use is not difficult for you anymore!

How Can You Estimate How Much Exterior Paint You Need?

Of course, painting a house’s exterior will take your more energy and effort than simply paint an interior room or ceiling. So, do you know what a house’s exterior paint includes?

What does a house’s exterior paint include?

Well, the primer, latex, enamel, acrylic, oil-based, water-based and specialty including anti-mold or anti-mildew belong to a house’s exterior paint. Among them, the primer is not a paint; however, it is considered as the first layer needed.

What do you need to consider when estimating the amount of exterior paint?

Let’s look at the calculating progress below carefully and you will see the usefunes in it! First, estimate the size of the body of the house. The easiest way is measuring the perimeter of the house. Then, you need to measure the height of the house from the foundation to the roofline, without gables included. Multiply these two numbers together.

Like painting an interior room, remember to subtract the area of doors and windows. The area of a normal window is usually 15 square feet and an average door is approximately 20 square feet. If your house has gables, multiply the width by the height of the gables, and divide by two. Do this for each gable and add the total to the measurement of the body of the house.

After that, you also have to estimate the amount of paint you need for the trim and gutter. As I said before, the whole exterior of the house is more complex! The average width of the trim is about 6 inches. Multiply the total length of the trim by 0.5 feet. Meanwhile, for the gutter, you need to determine its total length too. Each linear foot of the gutter is equivalent to 1 square foot. For example, for 40 feet of gutter, buy adequate paint to cover 40 square feet.

Here is one thing to take note! For the paint of a trim, the rule of thumb is 1 gallon for every 8 gallons of body paint. Now you have final results! When you add the trim and gutter calculations together, you’ll know the extra paint you need for them.

As usual, divide the measured square footage by 350 to find out the number of gallons of paint you need. You may also want to determine the number of paint coats. Just examine the surface you are going to paint. Refer to the below notes again to know the number of paint coats for each surface.

Let’s have a look at this example. Can you estimate how much exterior paint you have to use for a 1500-square-foot house?” Well, if you want to refresh your house with new paint and concern about the amount of paint needed for the painting, here’s the answer! So, a 1500-square-foot house may require from 12 to 15 gallons of paint with two coats, including the siding, overhangs, and soffits painting.

How much does it cost to paint a house’s exterior?

If you can’t do it yourself, you can hire a professional painting service and they will handle it in a flash. The location and the size of your house, as well as the company you hire, will directly decide the cost of painting the exterior of your house. These factors can dramatically change the overall cost of your painting.

However, here are some average costs for the paint of the exterior of a house for you to consult:

  • For the whole cost of paint and supplies, the price ranges from $1,100 to $1,350.
  • For the paint of a two-story house, the cost will reach nearly from $1,820 to $2000.
  • For the paint of a very large 3,000-square-foot house, the cost will reach from  $2,700 to $3,700.

What Are Basic Tools For A Paint Project?

In the market, there are millions of painting tools with various shapes, sizes and functions.

But you know, basic is the best. You only need some basic tools for a normal paint project, for example, a wall, door, window and so on.

In case you need to do a lot of sophisticated painting, you can find specialized tools.

Now, look at the list of fundamental tools and check whether you have them or not.

Tools For A Paint Project

  • Drop cloth. It can protect your furniture and floor.
  • Sandpaper. It can eliminate imperfections and enhance your painting quality.
  • Blue painter’s tape: It can protect painted trim and help you achieve perfect paint lines
  • Flat sash brush. It is suitable for painting flat surfaces.
  • Angled sash brush. It is useful for cutting in corners or painting edges.
  • Paint tray and disposable liners, which can be used with most paints and finishes. They help save your time and money by eliminating the cleanup of paint trays between coats or colors.
  • Trisodium Phosphate (TSP). It helps cleanse without leaving a residue.
  • Roller, and screw-on extension pole. They are crucial for coating walls and ceilings.
  • Paint spray. It brings some big advantages you can consider.
  • The paint application and drying process are fast. It can extend to areas that are difficult to reach but only requires one single coat to achieve good results and smooth finish.
  • Paint brush. This traditional method of painting is still the favorite choice of many people.

It offers an even and uniform level of coverage, and gives you full control of the paint lines. It may even require two or more coats or takes a lot of time, but you have to admit that the paint adheres to surfaces firmly and easily. Also, you can paint the nook and cranny better.

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What Are The Tricks Of Using Paint In An Economical Way?

The high-quality paint often comes with quite reasonable costs; therefore, there is an increasing concern about how to use paint proficiently and save more money. Follow our following tips:

Only use the high-quality paint for significant color changes.

I think there is no need to point out the great benefits high-quality paint brings us compared to cheap one. The expensive painting only requires one coat for cutting down on the amount of the total paint. And believe me, buying expensive paint once is much more economical than buying a cheap one several times to re-paint.

In fact, different colors of one type of paint can even have different levels of coverage. Certain colors may cover well in only a single coat, meanwhile, others require more than two coats.

Only purchase 80% of what you need

When you have done calculating how much paint is required, remember to buy 80% of that amount. Because when you are about to complete painting, you will know clearly how much you need to finish the remaining. This will prevent you from buying too much paint, thus saving your money and time!

Use rollers or spraying?

Have you ever decided whether you should roll or spray the house? It is hard to choose one! Do you know that rolling a house uses less paint but actually covers the siding and trim better?

Meanwhile, spraying cannot push paint into every crack like rollers, but you’ll save a lot of money on labor because the cost of spraying is half as much as paint rolling. Spraying also helps you get more protective paint on the house.

In short, there is no fixed answer about which one is better than the other. Everything has its pros and cons! You should consider what you need when you choose one of them.

Change a spray tip periodically

There is a fact that an old spray tip utilizes much more paint than a brand new one does. When the old tip wears out, the fan of the spray starts to blot in the center of where you are spraying. As a result, this uses more paint directly, and also creates a weak and uneven coat on the edges of the spray fan.

Bend your wrist while spraying

It sounds weird, right? However, it can be very effective! Many people pull their arm away when they are at the last steps of the sweep, thus producing an uneven spray and even paint buildup in the middle steps. So, it is suggested that you should always move your arm or wrist when you are doing a spraying job.

The ideal distance between you and the siding will be about 12 to 18 inches, and you always have to keep this distance!

Some Of The Best Paint Brands

You can check the below list of some of the best paint brands. They are completely affordable.

Benjamin Moore Regal Select: The plus point? It is very durable and easy for cleaning; therefore, it earns high marks across all criteria. By the way, the level of paint coverage is long-lasting as well.

Runner-Up: Valspar Signature: The characteristic of this paint brand is right in its name! It has excellent coverage and finish quality. Besides, it also receives high scores from demanding customers as well as in quality tests.

To Sum Up

So, this article today has provided you with comprehensive information you should know about paint. I hope this simple guideline will help you, especially to estimate the amount of paint you need or to use paint in an economical way.

Now you can easily find an answer for yourself “How much exterior paint do I need for a 1500 square foot house?” or what you can do if you have some amounts of paint?” If you have anything to ask or want to share what you know, tell us!

Thank you for reading!