Popular calculators

Enter dimensions below for walls, ceiling, fence, deck, or wallpaper — coats, waste, and coverage from your paint can, with a copyable shopping list.

Paint Calculator

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

Rooms

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Project settings

Paint
Stain
Surface

Default 10% for touch-ups

$

Your estimate

Enter room dimensions to see paintable area and gallon counts.

New to DIY? Read this first

Gallons first, then tools. Short answers you can use in the aisle — tap a card for the full how-to.

First paint job hub →

How to choose a roller

9-inch frame + 3/8″ nap for smooth walls. Go 1/2–3/4″ nap on texture.

  • Buy a metal frame that locks the cover. Spend on covers, not a fancy handle.
  • One spare cover per colour — shed or matted nap leaves fuzz in the paint.
  • Ceilings: use a dedicated cover so wall lint does not transfer.
Roller nap guide →

How to choose a brush

One 2–2½″ angled sash brush for cutting in. Skip cheap foam for walls.

  • Angled bristles follow trim and ceilings. A square 3″ brush is harder to control.
  • Synthetic bristles for latex (almost all interior wall paint in Canada).
  • Buy one good brush, not three dollar-store ones that fan out and leave streaks.
Brush size guide →

Tape off or drop cloths?

Both. Canvas (or taped plastic) on floors. Painter’s tape on trim and glass.

  • Drop cloths catch roller spray and tray drips. Tape does not protect a floor.
  • Blue or green painter’s tape on baseboards, window sash, and light-switch plates if you leave them on.
  • Pull tape at 45° while the last coat is still slightly tacky for a clean line.
Tape vs drop cloths →

What order do I paint?

Ceiling first, then walls, then trim last.

  • Cut in a 2–3″ band, then roll while that band is still wet (wet edge).
  • Finish one wall before you take a lunch break — a dry line shows as a stripe.
  • Remove outlet covers before you start. Tape the openings, not the plastic plates.
Step-by-step room →

How many coats?

Two finish coats on walls for most colour changes. Primer first on new drywall or stains.

  • Same colour refresh on sound walls can be one coat — still buy enough for two.
  • Wait the recoat time on the can (often 2–4 hours latex). Overnight is safer for beginners.
  • Dark-to-light usually needs primer plus two finish coats.
Coats & dry time →

What else is in the cart?

Tray + liners, extension pole, stir stick, sandpaper, putty knife, TSP substitute.

  • Extension pole saves your shoulders on walls and ceilings.
  • Liners mean you are not washing a tray between colours.
  • Calculate gallons first so you are not mid-wall at Canadian Tire.
Full supplies list →

Canadian paint brands

Typical interior coverage and where the can is sold. Open a brand for a 12×12 example, then use the calculator with the number on your lid. Not affiliated with any manufacturer.

Typical interior paint coverage by brand sold in Canada. Always use the number on your can.
BrandWhere it is soldTypical interior sq ft/gal12×12 walls, 2 coats
BehrHome Depot Canada350–4002–3 gallons
Benjamin MooreIndependent Benjamin Moore retailers across Canada (not big-box exclusive)350–4002–3 gallons
Sherwin-WilliamsSherwin-Williams stores and authorized dealers across Canada350–4002–3 gallons
Cloverdale PaintCloverdale Paint stores (Western Canada) and selected dealers350–4002–3 gallons
DuluxCanadian Tire, Home Hardware (selected), and Dulux/PPG retailers350–4002–3 gallons
SicoSico/PPG retailers, hardware independents — especially Quebec350–4302–3 gallons
Beauti-ToneHome Hardware (exclusive in Canada)350–4002–3 gallons
CILCanadian Tire and selected retailers (AkzoNobel)300–4002–3 gallons
ValsparLowe’s Canada and selected retailers350–4002–3 gallons

Brand names appear only so you can match typical Canadian label coverage. Paint Calculator is an independent tool — not affiliated with, endorsed by, or sponsored by Behr, Benjamin Moore, Sherwin-Williams, Cloverdale Paint, Dulux, Sico, Beauti-Tone, CIL, Valspar, PPG, The Home Depot, Lowe’s, Canadian Tire, Home Hardware, or their parent companies. Always use the Coverage figure printed on your can. Full disclaimer.

Project guides

View all

Primer, wall repair, prep checklists, and step-by-step painting — then use the calculator above for gallons.

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 cabinets and full-room plans, see the cabinet and trim guide and interior painting project guide. For wallpaper rolls, pattern repeat, and accent walls, try our wallpaper calculator or read our wallpaper roll guide.

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. A 12×12 room with 8 ft ceilings needs about 2–3 gallons for two coats.

How many sq ft does a gallon of paint cover in Canada?

Most interior latex covers 350–400 sq ft per gallon on smooth walls — Behr, Benjamin Moore, Sherwin-Williams, Cloverdale, Dulux, Sico, Beauti-Tone, CIL, and Valspar all cluster there. Enter the Coverage line from your can, not a generic average.

Which brands does this calculator work with?

Any brand that prints coverage on the can. We have dedicated pages for Benjamin Moore, Sherwin-Williams, Cloverdale, Dulux, Sico, Beauti-Tone, CIL, Valspar, and Behr (Home Depot). This site is not affiliated with any of them.

How much paint for a 12×12 room?

About 2–3 gallons for walls with two coats when the can lists ~400 sq ft/gallon. Use the how much paint calculator with your exact dimensions and can label.

What roller and brush should I buy?

9-inch roller with 3/8″ nap for smooth walls; one 2–2½″ angled sash brush for cutting in. Canvas drop cloth on the floor and painter’s tape on trim — you need both.

Should I tape off or just use drop cloths?

Both. Drop cloths protect floors from roller spray. Tape protects trim and glass. Tape is not a floor covering.

Does this work for fence or deck stain?

Yes. Choose fence stain, house exterior 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.