How to Paint a Room
A good paint job is about 85% prep. Clean and patch the walls, prime where you need to, then cut in and roll two coats keeping a wet edge, and the room looks pro. Use the calculator to buy the right amount and tap “Add to my materials list” as you go.
1Clean and prep the walls
Wash the walls (degloss any shiny surfaces), fill holes and cracks, then sand smooth and wipe off the dust. This prep is what separates a smooth finish from a patchy one.
2Tape, mask, and drop cloths
Run painter’s tape along trim and baseboards, lay down drop cloths, and remove or cover outlet plates and fixtures.
3Prime where needed
Prime bare drywall, stains, fresh patches, and big color changes — tint the primer toward your final color when going dark. Sound walls in a similar color can usually skip primer.
4Cut in the edges
With a 2½” angled brush, paint a 1½–2” band around the ceiling line, corners, and trim, working a section at a time so the cut-in stays wet when you roll into it.
5Roll two coats, keep a wet edge
Roll in a W pattern and fill it in, overlapping each pass and blending into the still-wet edge to avoid lap marks. Plan on two coats (one gallon covers ~350–400 sq ft); let the first dry per the label (~2–4 hrs for latex), and pull the tape while the final coat is still wet. The calculator sizes your paint and primer.