How to Paint a Room — Step-by-Step Guide with Materials List

Painting a room is one of the best-value DIY projects a homeowner can do. With the right prep and technique, a weekend job can look professional. Here's how to do it right.

What you’ll need

Materials:

Interior latex paint (2 gallons for an average bedroom)
Painter’s tape (2-inch width)
Primer (if painting new drywall or dramatic color change)
Spackling compound + 150/220-grit sandpaper
Drop cloths or canvas tarps

Tools:

9-inch roller and roller cover (3/8” nap for smooth walls; 1/2” nap for textured)
Paint tray and liner
2–2.5 inch angled sash brush for cutting in
Roller extension pole (6 ft makes rolling walls faster)
Stir sticks

Time: 4–8 hours for an average room (spread over 2 days with drying)
Cost: $60–$150 in materials for an average bedroom

How much paint to buy

Room size	Wall area (8 ft ceiling)	2 coats
8 × 10 ft	288 sq ft	2 gallons
10 × 12 ft	352 sq ft	2 gallons
12 × 12 ft	384 sq ft	2–3 gallons
12 × 16 ft	448 sq ft	3 gallons
14 × 20 ft	544 sq ft	3–4 gallons

Standard paint covers 350 sq ft per gallon per coat. For ceiling paint, calculate length × width separately and add 1–2 gallons.

Use the Paint Calculator for your exact room dimensions with openings subtracted.

Choosing the right paint finish

Finish	Sheen level	Best for
Flat/matte	None	Ceilings, low-traffic rooms
Eggshell	Low	Living rooms, bedrooms
Satin	Medium	Hallways, kids’ rooms — easy to clean
Semi-gloss	High	Trim, doors, bathrooms, kitchens
Gloss	Very high	Trim, accent details

Pro tips for a clean finish

Never skip filling holes — even small holes show through paint
Sand between coats — 220-grit removes any nibs or brush marks; wipe dust off before the next coat
Don’t skimp on tape — spend 20 minutes taping properly to save an hour of touch-up work
Keep a wet edge — always roll into wet paint to avoid lap marks
Buy 10% extra — leftover paint is useful for touch-ups for years; keep it stored upside-down in a cool location

Frequently Asked Questions

How many gallons of paint do I need for a room?

An average 10×12 ft room with 8-ft ceilings needs about 2 gallons for 2 coats of wall paint. Larger rooms (12×16 ft) need 3 gallons. Use the Paint Calculator for your exact dimensions and number of coats.

Should I use primer before painting a room?

Primer is necessary when: painting over a dark color with a light one, painting new drywall, covering stains, or painting over glossy surfaces. For same-color touch-ups or similar color changes, a self-priming paint works fine without a separate primer coat.

How long does it take to paint a room?

A 12×12 ft bedroom takes 4–6 hours for an experienced painter doing 2 coats with dry time. For a first-timer doing proper prep, plan 6–10 hours spread across 2 days. Cutting in (edges) takes longer than rolling the field.

What order do you paint a room?

Paint in this order: (1) ceiling first, (2) walls from top to bottom, (3) trim and doors last. Within each surface, cut in the edges with a brush before rolling the field. Always work wet-edge to wet-edge to avoid lap marks.

How long to wait between coats of paint?

Most latex wall paints need 2–4 hours between coats. Check the label — "recoat time" is specified per product. In humid or cold conditions, add 1–2 hours. Rushing a second coat over a tacky first coat causes peeling.