Paint Coverage Calculator

How It Works

This calculator estimates paint requirements by:

1. Wall Area: Calculates total wall square footage using the formula: 2 x (length + width) x height. This gives the combined area of all four walls.
2. Coverage: Assumes standard interior latex paint coverage of 350 sq ft per gallon. Premium paints may cover 350-400 sq ft, while budget paints may cover only 250-300 sq ft.
3. Coats: Multiplies the paint needed by the number of coats. Most color changes require 2 coats; painting over dark colors with light shades may require 3.

Tip: Buy 10-15% extra paint for touch-ups and to account for windows/doors using less area than calculated. Unopened paint cans can typically be returned to the store.

Paint Coverage by Type

Different paint finishes and formulations offer different coverage rates per gallon:

• Flat/Matte: 350-400 sq ft per gallon. Best for ceilings and low-traffic areas. Hides imperfections well but is harder to clean.
• Eggshell: 350-400 sq ft per gallon. The most popular finish for living rooms and bedrooms. Slight sheen, easy to clean, good durability.
• Satin: 300-350 sq ft per gallon. Ideal for kitchens, bathrooms, and hallways. Good moisture resistance and easy to wipe down.
• Semi-Gloss: 300-350 sq ft per gallon. Best for trim, doors, cabinets, and high-moisture areas. Very durable and easy to clean but shows wall imperfections.
• High-Gloss: 250-300 sq ft per gallon. Used for accent pieces, furniture, and front doors. Maximum durability but requires flawless surface preparation.
• Primer: 200-300 sq ft per gallon. Always prime bare drywall, wood, or when making dramatic color changes. Primer improves adhesion and ensures even color.

Room Painting Tips

• Subtract openings: A standard door is roughly 21 sq ft and a standard window about 15 sq ft. For rooms with many windows, subtract their area from the total for a more accurate estimate.
• Surface preparation matters: Clean walls with a damp cloth, fill holes with spackle, and sand rough spots. Proper prep is the difference between a professional-looking job and a messy one.
• Use painter's tape: Apply tape along trim, ceiling edges, and window frames for clean lines. Remove the tape while the final coat is still slightly tacky for the sharpest edges.
• Maintain a wet edge: Work in sections and always roll back into the wet paint to avoid visible lap marks. In warm, dry conditions, work faster to prevent the paint from drying too quickly.
• One gallon covers a small room: A typical 10x10 ft room with 8 ft ceilings has about 320 sq ft of wall area. One gallon is usually sufficient for one coat.