Paint Calculator: How Much Paint Do I Need?
Stop guessing and start saving. Our paint calculator tells you exactly how many gallons of paint do I need for any room — helping you avoid waste and unnecessary trips to the store.
Room Dimensions
Doors & Windows
Paint Settings
How many square feet does a gallon of paint cover? Most interior paints cover 350-400 sq ft per gallon. Primer typically covers 200-300 sq ft.
How Many Square Feet Does a Gallon of Paint Cover?
When figuring out how many gallons of paint do I need, understanding coverage rates is crucial. Different paint types and surface conditions affect how far your paint will go.
| Paint Type | Coverage per Gallon |
|---|---|
| Standard Interior Latex | 350–400 sq ft |
| Premium Interior Paint | 400–450 sq ft |
| Primer / Sealer | 200–300 sq ft |
| Exterior Paint | 250–400 sq ft |
| Textured / Porous Surfaces | 150–250 sq ft |
Our paint calculator square feet tool defaults to 350 sq ft per gallon, which works well for most smooth interior walls. Adjust this value if you’re working with textured surfaces or using specialty paints.
Eco-Friendly Paint Tips
Buy Only What You Need
Using a paint calculator prevents over-purchasing. Leftover paint is hazardous waste that requires special disposal.
Choose Low-VOC or Zero-VOC Paint
These formulas emit fewer harmful chemicals, improving indoor air quality and reducing environmental impact.
Dispose of Paint Properly
Never pour paint down drains. Take leftovers to a household hazardous waste facility or find local recycling programs.
Consider Recycled Paint
Many brands now offer quality recycled paint at lower prices — better for your wallet and the planet.
How to Use This Paint Calculator
Answering “how much paint do I need” takes just a few simple steps:
Step 1: Measure your room’s length, width, and ceiling height in feet. For irregular rooms, measure each wall separately.
Step 2: Count doors and windows. We automatically deduct 21 sq ft per door and 12 sq ft per window.
Step 3: Select your number of coats. Two coats is standard for best coverage and durability.
Step 4: Click “Calculate” to see exactly how many gallons of paint do I need for your project.