Brel's Blog

Our Guide to Calculating How Much Paint You’ll Need for Your Interior Painting Project

November 1st, 2016


Interior PaintingIt’s always better to make the necessary preparations before you begin a project. Showing up without a plan and winging it never works out well. When it comes to home improvement, estimating the need for paint and other supplies doesn’t seem to work in anyone’s favor, either. When we arrive to paint a home’s interior, we have already calculated exactly how much paint we’ll need. Here’s an overview of how we do it:

The Basics

The first thing you need to know when determining paint quantity is exactly how much square footage you’re looking at. Take every room you’re painting, and apply the following formula:

Add together the length of the walls in a room. Then, multiply the result by the height of the room, floor to ceiling. The resulting number is the room’s total square footage.

Once you have your total square footage, it’s easy to determine how much paint you’ll need. One gallon of paint covers around 350-400 square feet, so just divide square footage by 350 to get the required number of gallons. Calculate ceilings in the same way. Multiply the width of your ceiling by its length to get its square footage. Again, just divide by 350, and that’s how many gallons you should buy.

Add the calculated number of gallons necessary to cover each room’s walls, and then each room’s ceilings; this will give you the grand total paint quantity needed.

Don’t worry if your calculations result in fractions. Paint is available in quarts, as well. Remember: when in doubt, always buy more than you’ll use. Extra paint is great for a variety of other projects.

A Few Catches

When you’re working on a project, there’s always a catch, and painting is no different.

Remember that doors and windows total we said to hang on to? Well, this is where it comes into play. You can’t forget to add your door square footage to your final gallon total. The formula is the same (total square footage/350), but it’s easy to lose track of everything apart from walls and ceilings.

Trim and baseboards are another often-overlooked piece of the puzzle. Apply the same square footage to gallon formula listed above to calculate the amount of paint for trim.

Multiple coats of paint are the biggest hurdle in determining paint quantity. People overlook that unpainted drywall will absorb more paint, and that painting over a dark color will also take more coats of paint. Even one extra coat means doubling the number of gallons you need to purchase.

Hopefully, this tutorial has given you an easy way to determine how much paint to buy for your next interior paint job. It’s the same equation that we use professionally, so you can feel confident that it will work for you at home.

If you’re ever in need of a professional painting service in the Denver area, get in touch with us. There’s no job too big or small; we take care of them all.

What our customers are saying:

  • “Very thorough explanation of work to be performed & outlined in bid. Work crew was prompt and courteous & did exceptional work. When we needed to add to the contract & make changes, Brel was very easy to work with – and made himself available via phone/email/in person. We are very happy with the exterior & interior painting we requested of the company & would recommend to friends & family.”Kayce O’Brien