Paint Calculator
Estimate paint gallons needed for walls, ceilings, and trim
Length of the room
Width of the room
Height of walls
Standard door: 20 sq ft
Standard window: 15 sq ft
Most projects need 2 coats
Wall Area
—
sq ft
Paintable Area
—
sq ft
Paint Needed
—
gallons
Estimated Cost
—
USD
How to Use This Calculator
Buying the right amount of paint saves you time and money. Our paint calculator accounts for room dimensions, doors, windows, and number of coats.
- Measure room length, width, and ceiling height
- Count the number of doors and windows
- Decide how many coats you will apply
- Enter your measurements in the calculator
- Buy 10% extra for touch-ups
AI Insights
Smart analysis for your project
Smart Estimates
Our AI cross-references material costs, regional pricing, and project complexity for more accurate estimates.
Waste Optimization
AI-calculated waste factors based on project type, not flat percentages. Saves 5-15% on material costs.
Best Practices
Recommendations derived from building codes, contractor data, and thousands of completed projects.
Calculation Formula
Wall area = 2 x (L + W) x H
Paintable = Wall area - (Doors x 20) - (Windows x 15)
Gallons = (Paintable x Coats) / 350
Frequently Asked Questions
How much does a gallon of paint cover?
One gallon of interior paint typically covers 350-400 square feet with one coat.
How many coats of paint do I need?
Most projects require 2 coats. You may need 3 when painting over dark colors or on bare drywall without primer.