Paint Calculator

Estimate gallons of paint needed for interior rooms or exterior walls.

Dimensions
Length of the room to be painted.
Width of the room.
Height of the walls (ceiling height).
Details
1

-20 sq ft each

1

-15 sq ft each

2

sq ft/gal
Estimate

0

gallons

For 2 Coats

0

Liters (Metric)

Room Preview (Unfolded)
Perimeter: 44.0 ft × Height: 8 ft

Surface Area

0sq ft
Total
0m²
Total

Primer Needed

0gal
1 Coat Primer

Recommended for new drywall or when changing from dark to light colors.

Documentation

How It Works

We calculate the total wall area and subtract standard sizes for doors and windows.

Gross Area = 2 × (L + W) × H

Net Area = Gross - (Doors × 20) - (Windows × 15)

Total Paint = Net Area × Coats

Gallons = Total Paint / 350

Assumptions

  • Standard Door: 20 sq ft
  • Standard Window: 15 sq ft
  • Ceiling painting is NOT included in this estimate.
  • Coverage assumes smooth surface; textured walls may require 10-20% more paint.
How to Use

About the Paint Calculator

What it calculates

This paint calculator estimates material quantities and project costs for home improvement work. Estimate paint gallons for rooms and walls.

When to use it

Use before purchasing materials to reduce waste and budget more accurately for DIY or contractor projects.

Example

Adjust the inputs above to model your specific scenario with the Paint Calculator.

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