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🎨Paint Calculator

Calculate Your Paint Needs

Get the exact amount of paint you need for your walls. Our free paint calculator includes coverage estimates and cost calculations.

Project Details

Room Size Presets

ft
ft
ft
coats
$

Results

Wall Area

384.00 sq ft

Gallons Needed

1.9 gal

Estimated Cost

$67.20

💡 Pro Tip

Most paint covers about 400 square feet per gallon. Always buy a little extra for touch-ups later.

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Quick Answer

Paint estimates usually start with the project area or volume, then add a waste factor before converting the result into bags, pieces, bundles, panels, or gallons. Use this calculator when you need a fast material estimate before ordering supplies, comparing costs, or planning a construction project.

Best for

Contractors, builders, remodelers, and DIY homeowners who need a practical jobsite estimate.

Inputs needed

Start with the dimensions of the project, then choose material settings, price, and waste percentage.

How to estimate

The basic workflow is to calculate wall area, subtract openings, check coverage, then round up so you do not run short during installation.

How many square feet does a gallon of paint cover?

One gallon typically covers 350-400 square feet with one coat. For textured surfaces or dark colors, coverage may be less (250-300 sq ft).

Paint Coverage Formula

Gallons = (Wall Area - Openings) ÷ Coverage per Gallon

Calculate the total wall area, subtract windows and doors, then divide by the paint coverage (typically 350-400 sq ft per gallon). Multiply by number of coats.

Step-by-Step Guide

1

Calculate Wall Area

Measure each wall: height × width. Add all walls together for total surface area.

2

Subtract Openings

Measure and subtract the area of windows, doors, and other openings.

3

Check Coverage

Check the paint can for coverage rate - typically 350-400 sq ft per gallon.

4

Number of Coats

Multiply by 2 for two coats, which is recommended for most painting projects.

5

Round Up

Always round up to the next whole gallon for convenience.

Pro Tips

  • Buy all your paint at once to ensure color consistency.
  • Keep a record of the paint color and brand for touch-ups.
  • Use a paint calculator to avoid buying too much or too little.
  • Consider the finish - flat for ceilings, matte/eggshell for walls, semi-gloss for trim.
  • Store leftover paint properly for future touch-ups.

Frequently Asked Questions

How many square feet does a gallon of paint cover?
One gallon typically covers 350-400 square feet with one coat. For textured surfaces or dark colors, coverage may be less (250-300 sq ft).
Do I need primer?
Yes, primer is recommended for new drywall, bare wood, or when changing from a dark to light color. Primer helps paint adhere better and covers more evenly.
How long should I wait between coats?
Wait 2-4 hours between coats for latex paint. For oil-based paint, wait 24 hours. Check the paint can for specific instructions.
Should I buy paint in 5-gallon buckets?
For large projects, 5-gallon buckets are more economical and ensure color consistency. For small rooms, gallons are more practical.
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