With more than twenty years of practical experience in renovating, repairing, and enhancing residences, Lee has been offering home improvement guidance for many years.
When starting a painting project, the goal is to avoid overspending or underspending on the necessary paint. Purchasing insufficient paint means you’ll have to pause your work to make a trip to the store. On the other hand, buying excess paint leaves you with leftover cans that are difficult to dispose of properly.
Before you start painting, it’s important to determine the amount of paint required. Using a paint calculator can provide you with an accurate estimate tailored to your specific space. If you prefer to avoid the math, you can also buy paint in standard amounts suited for various room categories, like small bedrooms, powder rooms, medium kitchens, or large suites.
How to Accurately Determine Square Footage for Painting Projects
To accurately determine the amount of paint needed, first calculate the total area of the walls and ceiling, then include a percentage for waste, and finally, deduct the area of any cutouts.
Ensure you have sufficient paint for applying two coats. If you want to incorporate the ceiling into your painting project, be sure to factor in its square footage. When estimating paint for entire rooms, the coverage is typically around 350 to 400 square feet per gallon.
- Calculate Wall Area: To find the area of a wall, multiply its width by its height. Each wall’s area should be calculated separately. Once the areas of all the walls are obtained, sum these values to get the total wall area.
- To determine the ceiling area, multiply the width of one wall by the width of the wall next to it. This calculation does not take into account any ceiling features, including light fixtures or smoke detectors.
- Include Wastage: To calculate the wastage amount, multiply the total area of the walls and ceiling by either 10% or 15% (0.10 or 0.15). Then, incorporate this wastage figure into the overall total. Wastage takes into consideration losses due to spills and evaporation.
- Subtract Cutouts: Any areas that remain unpainted are considered cutouts. The total area of these cutouts must be deducted from the overall paint estimate for the walls, ceiling, and any excess.
Cutouts
Instances of cutouts include doors, windows, closets, built-in bookcases, shelves, and skylights. Certain cutouts, such as ceiling lights, toilet tanks, outlets, light switches, and mirrors, are often considered too minor to include in the overall count.
Quick Methods for Calculating Paint Amounts
Is there a quicker method to determine the amount of paint needed? Absolutely. You can skip two steps: the deduction of non-paintable surfaces and the addition of waste. Detailing every cutout can be a tedious task. By removing this step, the calculation becomes simpler. Instead, you can account for a waste factor of 10 to 15 percent to cover the cutout areas.
If you’re uncertain about the quantity of paint required, we’ve provided some typical estimates below. It’s a good idea to purchase an additional gallon to cover any unforeseen needs and to have on hand for future touch-ups.
Determining the Amount of Paint Needed for Bathrooms
| Room | Area (Floor/Walls) | Paint Quantity |
| Powder Room | 20/124 square feet | 1 gallon |
| Small Bathroom | 40/108 square feet | 1 gallon |
| Medium Bathroom | 120/252 square feet | 2 gallons |
| Large Bathroom | 160/316 square feet | 2 gallons |
Determining the Amount of Paint Needed for a Powder Room
- Area of the floor: 20 square feet
- Wall Area: 124 square feet
- Utilize: 1 gallon of paint
Since powder rooms lack bathtubs or showers, their walls are typically well-maintained, allowing for just two coats of paint with a single gallon to suffice. This estimate does not account for 20 square feet of wall space taken up by a single entry door. Additionally, powder rooms generally do not feature windows.
Determining the Amount of Paint Needed for a Compact Bathroom
- Area of the floor: 40 square feet
- Wall Area: 108 square feet
- Utilize: 1 gallon of paint
In a compact bathroom that has few issues with the walls, typically, a single gallon of paint will suffice. This estimate does not take into account the presence of a single entry door, a window, and 65 square feet of wall area designated for a bathtub and its surround.
Determining the Amount of Paint Needed for a Standard-Sized Bathroom
- Area of the floor: 120 square feet
- Wall Area: 252 square feet
- Utilize 2 gallons of paint.
In this bathroom assessment, the calculations do not take into account a window or a doorway, as well as 65 square feet designated for the tub and its surrounding area.
Determining the Amount of Paint Needed for a Spacious Bathroom
- Area of the floor: 160 square feet
- Wall Area: 316 square feet
- Utilize 2 gallons of paint.
In this spacious bathroom, two gallons of paint will adequately cover all wall surfaces, leaving some excess paint. This estimate does not take into account the wall space occupied by a window or an entry door. Additionally, the alcove tub and its surrounding area, which account for 65 square feet of wall space, are not included in the total.
Determining the Amount of Paint Needed for Kitchen Projects
| Room | Area (Floor/Walls) | Paint Quantity |
| Small Kitchen | 100/243 square feet | 2 gallons |
| Medium Kitchen | 200/383 square feet | 2 gallons |
| Large Kitchen | 300/515 square feet | 3 gallons |
Kitchens experience a lot of activity, which means they often need a comprehensive painting. However, the presence of base and wall cabinets typically limits the wall area, resulting in a reduced quantity of paint required. Opt for high-quality paint in eggshell or semi-gloss finishes to facilitate easier cleaning in the kitchen.
Determining the Amount of Paint Needed for a Compact Kitchen
- Area of the floor: 100 square feet
- Wall Area: 243 square feet
- Utilize 2 gallons of paint.
Consider buying two gallons of paint for various small kitchen styles. The wall space measurement does not include one door, one window, and 42 square feet of base and wall cabinets.
Determining the Amount of Paint Needed for an Average-Sized Kitchen
- Area of the floor: 200 square feet
- Wall Area: 383 square feet
- Utilize 2 gallons of paint.
For an average-sized kitchen, you will need two gallons of paint to apply two coats. The calculation of total wall space excludes one door, one window, and 62 square feet of space taken up by base and wall cabinets.
Determining the Amount of Paint Needed for a Spacious Kitchen
- Area of the floor: 300 square feet
- Wall Area: 515 square feet
- Utilize 3 gallons of paint.
The calculation for the amount of paint needed for a spacious kitchen takes into account the removal of two windows and a door from the overall wall area, as well as deducting 75 square feet for base and wall cabinets.
Determining the Amount of Paint Needed for Bedrooms
| Room | Area (Floor/Walls) | Paint Quantity |
| Small Bedroom | 150/345 square feet | 2 gallons |
| Medium Bedroom | 200/405 square feet | 3 gallons |
| Large Bedroom/Suite | 300/565 square feet | 4 gallons |
Bedrooms generally require more paint compared to other parts of the house. While the walls are typically in decent shape and seldom need more than two layers of paint, they often feature a significant amount of wall area. This is primarily due to the minimal presence of built-in features in most bedrooms.
Determining the Amount of Paint Needed for a Compact Bedroom
- Area of the floor: 150 square feet
- Wall Area: 345 square feet
- Utilize 2 gallons of paint.
The calculation for the sample net omits a window and two doors from the overall wall area. One of the doors is the main entrance, while the other is a single-width closet door that takes up 20 square feet of wall space that has not been painted.
Determining the Amount of Paint Needed for a Standard-Sized Bedroom
- Area of the floor: 200 square feet
- Wall Area: 405 square feet
- Utilize 3 gallons of paint.
A medium-sized bedroom typically requires approximately three gallons of paint. This estimate does not include one window and three doors. Among these doors, one is the main entry door, while the other two consist of a double-width closet door, which leaves 40 square feet of wall space unpainted.
Determining the Amount of Paint Needed for a Spacious Bedroom
- Area of the floor: 300 square feet
- Wall Area: 565 square feet
- Utilize 4 gallons of paint.
In this extensive calculation for the main bedroom, we have not included one entry door, one window, and two extra doors, as these are for a double-width closet that takes up 40 square feet of wall space that remains unpainted.
Understanding the Term: Main Bedroom
Numerous real estate organizations, including the Real Estate Standards Organization, have identified the term “Master Bedroom” as possibly discriminatory and suggest the use of “Primary Bedroom” as an alternative.
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