Calculate paint and primer needed for rooms
A paint calculator helps estimate how much paint you need to cover walls and ceilings. Proper paint estimation saves money and reduces waste by ensuring you buy the right amount.
Paint Needed = (Total Wall Area - Openings) / Coverage per Gallon
Most walls need 2 coats for even coverage. Use 1 coat for touch-ups over same color. Use 3+ coats when covering dark colors with light paint or for high-traffic areas.
Use primer on new drywall, over stains, when covering dark colors, or on glossy surfaces. Self-priming paints work for repainting similar colors but aren't as effective as dedicated primer.
Standard door: ~21 sq ft. Standard window: ~12 sq ft. Subtract these from total wall area for accurate paint calculations.
Flat/matte hides imperfections but is hard to clean. Eggshell and satin offer moderate sheen and washability. Semi-gloss and gloss are durable and easy to clean, ideal for trim and kitchens.
Unopened latex paint lasts 10 years. Opened paint lasts 2-5 years if sealed properly. Store in cool, dry place. Stir thoroughly before use. Discard if lumpy, smelly, or separated.
Yes, buy 10-15% extra for touch-ups, mistakes, and future repairs. Paint colors can vary between batches, so buying enough initially ensures consistency.