Skip to Content
For Professionals
For Your Home
For Industrial
For Your Home
How To Paint & Stain

Paint Calculator

Interior Paint Calculator

Planning a bedroom, living room, or bathroom refresh?
Our interior paint calculator estimates how many gallons you'll need based on your room dimensions. 

Units for Dimensions (length, width, height)

Room Dimensions

Number of Doors and Windows

Number of Coats

How We Calculate Your Interior Paint Needs

We calculate the total area of all four walls using your room’s length, width, and height. We subtract the estimated area of any doors and windows, then multiply the remaining paintable area by the number of coats selected.

Formula

[(Length × Height × 2) + (Width × Height × 2) − Doors & Windows] × Number of Coats

How We Calculate Your Exterior Paint Needs

We calculate the total exterior wall area using your home's perimeter and wall height. We subtract the estimated area of any doors and windows, then multiply the remaining paintable area by the number of coats selected.

Formula

[(Perimeter × Wall Height) − Doors & Windows] × Number of Coats

Frequently Asked Questions

How much paint do I need for a room?

Most rooms need 1 to 2 gallons for full coverage with two coats. Enter your room's square footage or wall dimensions into the calculator and we'll give you an estimated figure, factoring in doors, and windows.

How much paint do I need per square foot?

One gallon of paint typically covers about 350 to 400 square feet per coat. Since most walls need two coats, plan for roughly 175 to 200 square feet of wall per gallon. The calculator does this math for you automatically.

How much paint do I need for a bedroom?

An average bedroom takes about 1 to 2 gallons for walls with two coats, plus extra if you're painting the ceiling or trim. Enter your exact dimensions for an estimate.

Does the calculator account for doors, windows, and multiple coats?

Yes. Just enter the number of doors and windows and how many coats you're planning, and the calculator adjusts the paint quantity so you don't over or under buy.

How much paint do I need for a bathroom?

Bathrooms are usually small, often under a gallon for one coat, but choose a moisture resistant finish. Pop in your measurements to get the amount, then shop bathroom ready paints right from the results.

Frequently Asked Questions

How much paint do I need for the exterior of my house?

A typical house exterior needs about 6 to 10 gallons for two coats, depending on size and surface texture. Enter your home's measurements into the calculator for a gallon count.

How much exterior paint do I need per square foot?

One gallon covers roughly 250 to 350 square feet per coat on exterior surfaces, less on rough textures like stucco or brick

How much paint do I need for siding?

Siding usually takes 2 coats for even, weather resistant coverage. Enter your total siding area and the calculator tells you how many gallons to buy.

For Industrial and Protective Coatings, OEM Manufacturing and General Maintenance Coatings. Find a local Cloverdale Paint representative near you.