Free paint calculator for any room. Enter your measurements and get instant results - gallons needed, cost estimates, and coverage area. โจ
Enter your room dimensions to get started
Tell us about doors, windows, and paint coats
This paint calculator tells you exactly how much paint to buy for any room. Just measure your space, enter the numbers, and get instant results. No confusing formulas, no guesswork, no trips back to the store because you bought too little (or wasting money buying too much).
Our paint calculator accounts for doors, windows, multiple coats, and uses realistic coverage numbers (350 sq ft per gallon, not the optimistic 400 sq ft paint companies claim). Whether you're painting a bedroom, living room, or entire house, this calculator gives you accurate results.

Get accurate paint estimates in 4 simple steps. No guesswork, no waste, no running out mid-project. โจ
Grab a tape measure and get the length, width, and ceiling height in feet. Don't include baseboards or crown molding - just basic wall-to-wall measurements.
Walk around the room and count doors and windows. Each door saves about 21 sq ft, each window about 15 sq ft - the paint calculator subtracts these automatically.
Most paint jobs need 2 coats. Going from dark to light? Pick 3 coats. The paint calculator adjusts the total gallons based on your choice.
Click "Calculate Paint Needed" and instantly see gallons required, paintable area, and cost estimates for budget, quality, and premium paint.
See exactly how any paint color will look in your actual room before you buy a single gallon.
๐จTry Colors on Your WallsโAvoid costly mistakes and get professional results with these insider secrets from painting pros. ๐ฏ
Whatever the paint calculator tells you, buy one extra gallon. You'll need it for touch-ups, and custom colors can't be perfectly matched later. That $40 now saves you from repainting an entire wall in six months.
๐ฐMoney-saving tip: Most hardware stores accept returns on unopened paint cans, so extra gallons aren't a risk.
Cheap paint ($20-25/gallon) seems like a deal until you need 3 coats and it still looks streaky. Quality paint ($35-45/gallon) covers better, lasts longer, and often needs fewer coats. The paint calculator shows costs for all quality levels - do the math on coverage vs. price.
๐Recommended brands: Behr Premium Plus, Sherwin-Williams Duration, Benjamin Moore Regal Select
That perfect "warm gray" on the paint chip might look blue, purple, or brown on your actual walls. Lighting changes everything. Before using the paint calculator to buy gallons, test colors in your actual room with your actual lighting.
Better option:
Upload a photo of your room and see any color on your walls instantly - way easier than buying sample pots.

See the transformation: Before vs After painting
The paint calculator tells you how much paint to buy, but it can't make your walls smooth. Fill holes, sand rough spots, clean walls, and tape edges before opening a paint can. Good prep makes average paint look great. Bad prep makes expensive paint look terrible.
The paint calculator assumes painted walls. If you're painting new drywall, covering dark colors, or painting over stains, you need primer first. Don't trust "paint + primer in one" marketing - real primer is a separate product.
โ ๏ธNeed primer if: Bare drywall, dark-to-light color change, stains or water damage, porous surfaces like wood or plaster

Proper room preparation with paint supplies ready
Paint cans claim one gallon covers 400 square feet. That's true under perfect lab conditions with perfectly smooth walls and professional application. In your actual house? You're getting 300-350 sq ft per gallon. Our paint calculator uses 350 sq ft, which is realistic for most homes.
Wall texture: Rough or textured walls use 20-30% more paint than smooth walls
Paint color: Dark colors and bold shades often need extra coats for even coverage
Application method: Spraying uses more paint than rolling; rolling uses more than brushing
Surface porosity: Unpainted drywall, wood, or plaster soaks up extra paint
Paint quality: Cheap paint has less pigment and needs more coats
If your walls are textured, porous, or you're painting a bold color, add 20% more to what the paint calculator recommends. Better to have extra than to run out mid-project with no way to match the color perfectly.


Living rooms usually have large windows and multiple doors. The paint calculator automatically subtracts these, but measure carefully - that big picture window saves you half a gallon.
Tip: Use eggshell or satin finish for easy cleaning in high-traffic areas
Bedrooms typically have fewer windows and doors. Use the paint calculator as-is, but consider an accent wall to add personality without painting the entire room.
Tip: Flat or matte finish hides wall imperfections and creates a cozy feel
Kitchens have cabinets, appliances, and tile backsplashes that reduce paintable area. The paint calculator handles doors and windows, but you'll likely need less than calculated due to cabinets.
Tip: Use semi-gloss or satin for easy cleaning of cooking splatters
Bathrooms are small but humid. The paint calculator gives accurate results for area, but invest in moisture-resistant paint to prevent mold and peeling.
Tip: Semi-gloss finish resists moisture and cleans easily
Used the paint calculator and know how much you need?
Now see exactly what any color looks like in your room with your lighting and furniture. Upload a photo and try thousands of colors instantly.
Visualize Paint Colors Free โWorks with any paint brand โข See results in 30 seconds โข No signup required
The paint calculator asks for number of coats - don't skip this! One coat almost never looks good. Budget for two coats minimum, three if going from dark to light.
This paint calculator is for walls only. Ceilings need separate calculation: length ร width รท 350 = gallons needed. Most standard rooms need 1-2 gallons for the ceiling.
Paint cans say 400 sq ft per gallon. Real world is 300-350 sq ft. Always use a paint calculator with realistic numbers, not marketing claims from paint manufacturers.
Don't use the paint calculator to buy 5 gallons of a color you've never seen on your walls. Test first - either with sample pots or by visualizing digitally. Colors look completely different in your actual lighting.
Whatever the paint calculator says, add one gallon. You'll need it for inevitable touch-ups, and custom colors can't be matched perfectly later. That extra gallon will save you from repainting entire walls.

Get answers to the most common questions about using our paint calculator and painting your room. ๐จ
You used the paint calculator and know exactly how much to buy. But do you know if that color actually works in your room?
See any paint color on your walls before buying gallons. Upload a room photo and try thousands of colors instantly. Way easier than buying sample pots and painting test squares.
Try Paint Colors Free โFree forever โข No signup โข See results in 30 seconds