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Paint Calculator
Calculate the amount of paint needed for your walls
Room dimensions
ft
ft
ft
Walls configuration for painting
Select the walls and ceiling you want to paint—click one to select or deselect it. Use the “Add window” and “Add door” buttons to subtract openings.
13 ft
10 ft
8 ft
13 ft
8 ft
10 ft
8 ft
13 ft
8 ft
10 ft
Material details
Paint
USD
gal
sq ft/gal
How many square feet one gallon covers in a single coat—check the label on the can.
A whole number from 1 to 5, usually 2.
Added to paint and primer before the result is rounded up to whole cans. 0 to 50%.
A big change of color usually needs 3 coats.
Paint coverage is provided by the manufacturer and may vary depending on the type of paint and surface.
Primer
Masking tape
Calculation completed!
The required amount of materials has been calculated based on the provided dimensions.
Dimensions summary
Selected surfaces-
Room dimensions-
Area to paint-
Coats of paint-
The area has been calculated after subtracting window and door areas.
Required materials
Paint
Needed amount-
Number of cans-
Cost-
Primer
Needed amount-
Number of cans-
Cost-
Masking tape
Tape length-
Number of rolls-
Cost-
Tape is counted along the top edge of the selected walls only (the whole room perimeter when the ceiling is selected), not along the floor or the corners.
Paint needed is the area to paint times the number of coats, divided by the coverage. The extra percentage is added to paint and primer, then the result is rounded up to whole cans.
This calculator provides estimated values. In practice, the amount of paint needed may vary depending on the type of paint, wall condition, and painting technique.
Total cost
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Paint is one cost. What will the whole room cost?
From a description or a photo of the floor plan, AI Renovation Calculator works out materials, fittings and labor for the entire renovation.
Common questions from renovation communities
Example questions and answers drawn from renovation community discussions. Usernames, vote counts and timestamps are illustrative and are not quotes from specific posts.
r/renovationToolsApps
47h ago
Selecting the Right Materials
What paint should I choose for different rooms?
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RrenoGuru•9h ago
well, it really depends! for bathrooms and kitchens, definitely go for something with good moisture and stain resistance (washable or latex paints). in living rooms and bedrooms, regular acrylic paints with matte or satin finish work great. for ceilings, i always use special ceiling paints because they have better coverage. and for exteriors... only use facade paints! otherwise you'll be repainting way too soon 😉
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NNexion21•2h ago
This was really helpful for me, thanks!
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Zzombiebacchus•7h ago
look at the consistency - good paint is thick like cream and doesn't drip off the stirrer. check the coverage rating on the package too, better paints cover more area. it's worth investing in pricier paint because it usually has better hiding power (fewer coats needed!) and lasts longer. if you're technically minded, check the contrast ratio (closer to 100% is better) and scrub resistance (class 1 and 2 are best)... but honestly, most people just look at price and brand 🙃
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Hhandyman123•5h ago
not always, but... on new walls, absolutely yes! also after removing wallpaper or when changing from dark to light colors. if you have any moldy spots, you'll want to prime those too (after drying and treating with fungicide!). on normal, previously painted walls in good condition - you can skip priming. i usually prime everything anyway because the paint adheres better and i end up using less of it... worth it! 👍
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142
Ssmoof99•3h ago
rough estimate? a 10x13 ft room with 8 ft walls has about 370 sq ft of wall (not counting the ceiling). at 350 sq ft per gallon that's roughly 1 gallon per coat, a bit less once you subtract the door and windows. two coats with 10% extra come to about 2-2.5 gallons, so three 1-gallon cans. i always add that 10% extra (it's the calculator's default too) because nothing's worse than running out of paint halfway through... nightmare! 😱 remember that the coverage on the can is optimistic theory, and dark colors always have lower coverage than light ones... so better to have a bit extra on hand.
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r/renovationToolsApps
33h ago
Surface Preparation
How should I prepare walls before painting?
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tileExpert11h ago
start by removing anything that's peeling and patch holes with spackling compound... then make sure to wash the walls with soapy water to remove grease and dirt (especially in kitchens!). once dry, sand down the patched areas and prime if needed. and protect everything with masking tape and plastic sheeting - floors, windows, outlets. seems like a lot of work, but trust me... preparation is 80% of success! i tried rushing it once without proper prep and had to redo everything... 🤦♂️
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DIYPro8h ago
sure you can! but only if the old paint is still well-adhered and not flaking off. you should still wash the walls before painting to remove any grease... and if the old paint is glossy, take some fine sandpaper and rough it up a bit - otherwise the new paint won't stick well. when changing from dark to light color, definitely use a primer first, or else you'll be painting 5 coats and the old color will still show through... speaking from experience here 😅
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fixItFelix1h ago
Great advice, saved me a lot of trouble.
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homeRenovator4h ago
oh boy, stains are the worst... for water marks, nicotine or grease, a special stain-blocking primer is your best friend - expensive but works wonders! for rust stains, use anti-corrosion primers. mold? treat with fungicide and make sure it's completely dry before painting, or it'll come right back... for really stubborn stains, use stain-blocking paint or special primers. i once battled water stain marks 3 times before using a good sealing primer... what a waste of time that was... 🙄
r/renovationToolsApps
33h ago
Painting Techniques
In what order should I paint a room?
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tileMaster6h ago
i always start with the ceiling! then work down to the walls, painting from top to bottom. first use a brush for all the corners, edges around ceilings and floors, around outlets... then use a roller for the larger surfaces. if you're also painting trim and door frames, leave those until after the walls have dried. i did it the other way around once and had to touch up all the trim... definitely not recommended 😂
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fixItFelix15h ago
the key is a good roller! use short-nap rollers (1/4-1/2 inch) for smooth walls, and longer nap (1/2-3/4 inch) for textured surfaces. apply paint in a W or M pattern, then fill in the spaces. important - paint the entire wall in one go! if you leave half a wall for later, you'll see the joins... don't press too hard with the roller and avoid painting when the sun is shining directly on the wall. oh, and don't thin the paint too much - that's a common mistake! 🎨
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smoof994h ago
Finally someone explaining this clearly!
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renoGuru3h ago
manufacturers usually say 2-4 hours... but it depends! latex paints dry faster than acrylics. always check the can. full curing is another story - that takes 7-14 days and until then, avoid scrubbing the walls. in humid rooms or with poor ventilation, drying time increases... patience pays off, though i know it's hard to wait 😊 sometimes i get impatient and apply the second coat too early... and then regret it when the paint smudges...
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Nexion211h ago
honestly? yes... almost always. one coat rarely gives nice, even coverage. when changing to a completely different color (like red to white) you might even need three coats! only some very expensive premium paints with good hiding power might work in one coat, especially if you're just refreshing the same color. i tried to save time once with just one coat... the result was... well, i had to apply a second coat anyway 🤷♂️
r/renovationToolsApps
16h ago
Common Painting Problems
How to avoid drips and streaks on the wall?
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handyman12314h ago
first off - don't thin the paint too much! use good quality rollers (the cheapest ones are a nightmare...) and paint methodically, in one direction, in sections about 3-5 feet wide. crucial point - always keep a “wet edge”, meaning don't let the paint dry at the edges before you paint the adjacent area. also avoid painting in hot weather or with open windows creating drafts - paint dries too quickly and then you get streaks... learned this from my own mistakes 🥵
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smoof9910h ago
ugh, classic problem! most often because of: poor surface preparation, painting over greasy/dirty walls (kitchens!), applying paint to fresh plaster/drywall, using the wrong type of paint (like acrylic over oil-based without primer) or moisture problems in the wall. once it happens... you need to remove the peeling paint, repair the surface and definitely prime before repainting. i had this happen in my bathroom... all the paint came off after 3 months because i didn't wait for the wall to dry after renovation... what a nightmare that was 😩
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DIYPro6h ago
i recommend microfiber or mohair rollers - they leave fewer marks. most important - don't let paint dry at the edges! if you already see marks, you can gently go over the dry wall again with a slightly dampened roller with a small amount of paint... sometimes helps. as a last resort, after it dries, you can lightly sand and apply an additional coat... but better to avoid this and paint properly from the start. some people say you can fix it without repainting... don't believe it! 😏
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tileMaster3h ago
This is gold! Wish I knew this earlier.
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zombiebacchus2h ago
ahh, my favorite problem... 😅 first of all - paint needs the right consistency, not too thin! don't overload your roller - dip it only halfway into the tray and tap off excess. ceiling-specific paints are great for ceilings because they're thicker. use short-nap rollers for ceilings. paint slowly, with moderate pressure, applying thin layers... and always, ALWAYS protect your floor and furniture with drop cloths. once i painted my hair white while doing a ceiling... my wife laughed for a week!
r/renovationToolsApps
32h ago
Maintaining Painted Surfaces
How to clean painted walls without damaging the paint?
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homeRenovator18h ago
gently... very gently! use a soft, slightly damp (not wet!) cloth with a mild detergent. wipe stains lightly, don't scrub like crazy... if you have paint labeled as “washable” or “scrub resistant” (class 1-2), you can clean a bit more intensively. always test cleaning in an inconspicuous spot first! avoid harsh chemicals and abrasives. i once scrubbed too hard and made a light spot on a colored wall... looked funny but had to repaint the whole section... 😔
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handyman1231h ago
Perfect explanation, solved my problem instantly.
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tileMaster12h ago
paint feels dry to the touch after a few hours, but that's deceptive! full curing takes 7-14 days, depending on the type of paint, temperature and humidity. best to wait at least a week before drilling, applying tape or hanging heavy items... lighter pictures on small hooks can be hung after 2-3 days. i remember when we stuck tape to fresh paint... when removing it, the paint came off right down to the bare wall 🙈 so really, have patience...
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fixItFelix5h ago
depends where... in living rooms and bedrooms, usually every 3-5 years is fine. kitchens and bathrooms, due to moisture and dirt, more often - every 2-3 years. hallways, especially if you have kids or pets, might need refreshing every 2-4 years. a lot depends on paint quality too - more expensive, good quality paint will look good longer... i always prefer to pay more for good paint than paint more often! the result is not only nicer but more durable... and less work in the long run 👌
Why Use Our Paint Calculator?
Benefits of the Paint Calculator
- Accurate material estimates for your specific room dimensions
- Customizable wall selection to match your exact project needs
- Accounts for windows, doors, and other openings for precise calculations
- Helps calculate multiple coats of paint required for proper coverage
- Includes primer and masking tape calculations for complete project planning
Problems Our Calculator Solves
- Eliminates guesswork when purchasing paint, reducing waste and extra trips to the store
- Prevents buying too little paint and running out mid-project
- Helps accurately budget for your painting project before starting
- Allows for proper planning of material needs for multi-room projects
- Simplifies the math for rectangular rooms—three measurements, plus any windows and doors
How to Use the Calculator
- 1Enter your room dimensions in feet (width, length, and height)
- 2Select which walls you want to paint using the interactive room visualizer
- 3Add any windows or doors to get a more accurate calculation
- 4Enter paint details: price and size of a can, coverage, number of coats and extra paint
- 5Add optional materials like primer and masking tape if needed
- 6Click “Next” to get your complete paint requirement calculation
Potential Savings
Using our Paint Calculator can help you save money in several ways:
- Reduce overpurchasing of paint by up to 20% compared to rough estimates
- Fewer spare cans—buy the number of cans you actually need instead of one or two extra “just in case”
- Decrease waste of unused paint that often dries out before being used
- Potentially save 15-25% on your total painting materials budget
- Reduce costs associated with multiple trips to the store for additional materials
For a typical room, good planning usually means one or two fewer cans of paint (roughly $30-$80) and no extra trips to the store.