You can apply paint to an average-sized bedroom (approximately 150 square feet) in about two hours. However, additional time is needed for preparation and cleanup. It could take anywhere from half a day to several days to paint an average room, depending on complications.
Clean the Room
Before painting, the room must be thoroughly cleaned of all dust and debris. Remove furniture, accessories, switch-plate covers and light fixtures from the room.
Repairs and Masking
Inspect walls and molding for dents and gouges, and make all repairs before painting. Edge all windows and doors with masking tape to prevent drips.
High or rounded walls and ceilings may require awkward, time-consuming brushwork. Bumpy wall textures require more time to finish and absorb more paint.
If you are painting over a bright color, you will need to apply primer first. If you are painting on a bright color, you will probably need to apply two coats. In either case, your painting time is instantly doubled.
If you're using good quality paintbrushes or rollers and want to preserve them for future projects, spend at least 20 minutes thoroughly cleaning each brush and roller.