Free Paint Calculator

Find out exactly how much paint you need for any room. Enter your wall dimensions and get precise paint quantity estimates including doors and windows.

Paint & Wall Square Footage Calculator

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Paint needed

About the Paint Calculator

A paint calculator eliminates the guesswork from home improvement projects. By entering your room dimensions, you get an exact estimate of how many gallons of paint you need, including coverage for multiple coats and accounting for doors and windows.

Quick Start Guide

  1. Enter your values — Fill in the fields with numbers relevant to your paint calculation. Most fields include sensible defaults.
  2. Adjust settings — Change options like units, rates, or timeframes to match your specific scenario.
  3. Review results — The output shows a clear breakdown so you understand how the total was calculated.

How It Works

Calculates total wall area = perimeter × wall height. Subtracts standard door (20 sq ft) and window (15 sq ft) areas. Standard paint coverage = 350-400 sq ft per gallon per coat. Includes a 10% waste factor and recommends primer for bare walls.

Real-World Example

Scenario: Painting a 12×14 foot bedroom

  1. Room dimensions: 12 ft × 14 ft with 8 ft ceilings.
  2. Openings: 1 door, 2 windows.
  3. Coats: 2 coats.
Result: Total paintable area: ~368 sq ft. Paint needed: ~2.1 gallons (round up to 2 gallons + 1 quart). Tip: buy 2 gallons and a quart — you'll have enough for touch-ups.

Who Is This For?

This paint calculator is designed for Homeowners planning improvement projects, comparing material costs, and estimating renovation budgets.. It's intentionally simple — no complex signup forms, no data tracking, no distractions. Just enter your numbers and get the answer.

Pro Tip

Always add 10-15% buffer to material estimates — waste, mistakes, and unexpected issues are part of every home project.

Things to Know

The paint calculator provides instant, accurate results based on standard formulas and the values you enter. Whether you are planning a financial decision, tracking a health metric, or solving a practical problem, this tool gives you the numbers you need without requiring signup or account creation.

How to get the best results: Use accurate, up-to-date inputs for the most reliable calculations. When planning ahead, run multiple scenarios with different assumptions to understand the range of possible outcomes.

Note: This tool is designed for educational and planning purposes. For critical financial, medical, or legal decisions, always verify the results with a qualified professional who can evaluate your specific circumstances.

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Frequently Asked Questions

How accurate are the results?

Results are based on standard formulas and the values you enter. They are accurate for educational and planning purposes.

Is this tool really free?

Yes, completely free. No signup, no hidden charges, no usage limits. Use it as often as you need.

Can I share the results?

Yes. You can take a screenshot or share the page link with anyone. The tool works the same for everyone.

How to Use the Paint Calculator

Measure your room's length, width, and wall height. Enter the number of doors and windows to subtract their area. Select how many coats you plan to apply.

  • Standard door: ~21 sq ft (3' x 7')
  • Standard window: ~15 sq ft (3' x 5')
  • Paint coverage: 1 gallon covers ~350 sq ft

Paint Coverage Formula

Total Area = Perimeter × Wall Height
Paint Needed = (Total Area - Doors & Windows) ÷ 350 × Coats

Frequently Asked Questions

Measure the wall's width and height, multiply them for square footage, then divide by 350. For a 12' x 8' wall with one coat: 96 ÷ 350 = 0.27 gallons (about 1 quart).
This calculator estimates wall paint only. Ceilings typically take 1-2 gallons depending on room size.
Buy 10% extra for waste, touch-ups, and future repairs. If the calculator says 1.2 gallons, buy 1 gallon and 1 quart.