Interior Paint Calculator

Estimate interior paint requirements for walls, ceilings, doors, and trim. Accounts for room dimensions, number of coats, and surface preparation.

Interior Paint Calculator

Professional estimation based on industry standards

Room Measurements(in feet)

Room 1

Door 1
Window 1
Window 2

Paint Specifications

Wall Paint

💡 Standard Practice: New/unpainted surfaces get 1 coat primer + 2 coats paint. Previously painted surfaces typically need 2 coats of paint only.

Ceiling Paint

Calculation Standards:

  • • Industry coverage: 350-400 sq ft/gal (smooth surfaces)
  • • Primer coverage: 200-300 sq ft/gal
  • • Variable door/window sizes (10-40 sq ft)
  • • PCA & MPI professional standards
  • • Includes waste factors & adjustments
📚

Want to Learn More?

Paint & Decorating Retailers Association standards, 350-400 sq ft per gallon coverage rates, and primer requirements.

Read the Interior Paint Coverage Guide

How to Use This Calculator

  1. Enter room dimensions: Input room length, width, and ceiling height.
  2. Subtract openings: Deduct area for doors and windows.
  3. Select surfaces: Choose to paint walls, ceilings, trim, or all.
  4. Number of coats: Specify coats needed (typically 2 for walls).

Interior Paint Coverage

One gallon covers approximately 350-400 sq ft per coat on smooth surfaces. Textured walls or dark colors may require additional paint.