Paint Coverage Calculator
Achieve professional results and avoid material waste with our interactive painting modeling tool.
Total Material Required
8.00
Gallons (US)
Metric Conversion
30.3 L
Total Coverage
240 m²
Coverage Note
Standard paint coverage is 25-35 m² (300-400 sq ft) per gallon. Textured or porous surfaces may require 20% more paint.
Wall Surface Calc
Total Area = (Perimeter × Height) - (Openings). Subtract roughly 1.5 m² for each standard window.
Surface Material Modeling
- Select your preferred Unit System (Metric m² or Imperial sq ft).
- Enter the total Target Surface Area of the walls to be painted.
- Input the Coverage Rate of your specific paint (350-400 sq ft/gal is standard).
- Set the Number of Coats you plan to apply.
- Observe the Material Volumetric Model showing the total paint volume.
- View the Total Gallons and Total Liters required for the job.
- Click Copy Paint Report to save the estimates for your trip to the paint store.
Frequently Asked Questions
How much area does one gallon of paint cover?
On average, one US gallon of paint covers between 350 and 400 square feet (32–37 m²) of smooth wall surface. Textured or porous surfaces like brick or raw drywall will require more paint.
How many coats of paint do I need?
For most interior projects, 2 coats are recommended for a professional finish. If you are painting a light color over a very dark color, a primer coat plus 2 or 3 coats of paint may be necessary.
Do I need to subtract windows and doors?
Yes. To get an accurate estimate, subtract the area of all openings. A standard door is about 20 sq ft (1.8 m²) and a standard window is about 15 sq ft (1.4 m²).
What is the conversion for Liters?
One US gallon is approximately 3.785 liters. Our calculator provides both units automatically for international and local bucket sizes.
Interior Design Benefits
- Instant Paint Volume and Gallon Count algorithms
- Visual material volumetric modeling preview
- Supports multiple coats and custom coverage rates
- Automatic metric and imperial conversion
- 100% private — your room data stays local
- Mobile-optimized for checking orders at the hardware store
Privacy-First Architecture
100% Local Processing
Unlike traditional online tools, Paint Coverage Calculator processes your data entirely within your browser. Your files, numbers, and private info never reach our servers, ensuring absolute confidentiality.
Lightning Fast Speed
By eliminating the need for server uploads and downloads, we provide near-instant results. This technical approach saves bandwidth and provides a seamless user experience on both mobile and desktop.
Professional Grade Utility
The Paint Coverage Calculator is part of the Toolkits Plus suite—a comprehensive collection of professional-grade utilities designed for modern digital workflows. Whether you're a student, professional, or hobbyist, our tools provide accurate, verified results without the clutter of traditional "thin" web applications.