Paint Calculator

Enter room dimensions and ceiling height. Get paintable square footage and gallons to buy.

Rooms

ft
in
ft
in
ft
in

Project settings

Paint
Stain
Surface

Default 10% for touch-ups

$

Your estimate

Enter room dimensions to see paintable area and gallon counts.

How it works

  1. 1. Measure roomsEnter length, width, and ceiling height in feet and inches for each rectangular room.
  2. 2. Set product & coatsPick paint or stain (fence, house exterior, deck), adjust coats, coverage from your can, and openings if needed.
  3. 3. Buy with confidenceWe calculate gallons (and quarts) and let you copy a shopping list for the paint counter.

Paint, stain & wallpaper

Use the calculator above for paint and stain. For wallpaper rolls, pattern repeat, and accent walls, try our wallpaper calculator.

FAQ

How much paint do I need for a room?

Wall area = 2 × ceiling height × (length + width). Add ceiling area if needed. Multiply by coats, add waste, then divide by sq ft per gallon on your paint label.

How many sq ft does a gallon cover?

Most interior latex covers 350–400 sq ft per gallon on smooth walls. Primer is often 300 sq ft/gallon. Check your can — enter the exact number for best results.

Does this work for fence or deck stain?

Yes. Choose Fence stain, House stain, or Deck stain. Fence uses run length × panel height; deck uses length × width; house stain uses building footprint and wall height.

Can I calculate multiple rooms?

Yes. Add up to five rooms and the calculator totals paintable area and gallons for the whole project.