Calculate exactly how many gallons of paint you need. Accurately subtracts doors and windows, and includes ceilings and multiple coats.
Walking down the paint aisle can be overwhelming. Beyond just picking a color, you have to choose a "sheen" or "finish." The sheen determines how much light the paint reflects, how durable it is, and how easy it is to clean. Using the wrong sheen is the #1 mistake DIYers make.
For 90% of your interior home projects, you should be buying 100% Acrylic Latex paint. It dries fast, has low VOCs (meaning it doesn't smell bad or release harmful chemicals), and cleans up easily with soap and water.
When should you use Oil-Based paint? You should only use oil-based (alkyd) paint when you are painting raw metal (like a radiator to prevent rust), when you are painting over a surface that already has multiple layers of old oil paint, or when you need an ultra-hard finish for a floor or porch. Oil-based paint takes 24 hours to dry to the touch and requires mineral spirits for cleanup.
Professional painters will tell you a secret: Painting is actually 20% applying the color and 80% preparation. If you skip prep, your paint will peel, bubble, or look streaky within a year. Follow this exact checklist before you open your first can of paint:
Yes, in 90% of cases. One coat rarely provides uniform color depth. Two coats ensure a rich, durable, and washable finish.
Kitchen cabinets require specialized enamel paint. A general rule is 1 gallon of cabinet enamel for every 15-20 linear feet of cabinetry (assuming 2 coats).
This calculator estimates your topcoat paint. If you are painting bare drywall or making a drastic color change, you should buy an equal amount of primer using the same square footage calculation.
For standard latex paint, wait at least 2 to 4 hours. If the room is humid or cold, it may take up to 6 hours. If you apply the second coat too early, the roller will pull the first coat right off the wall.
If you are using latex paint, run the roller under warm water until the water runs clear. Squeeze it out, wrap it in plastic wrap, and put it in the freezer. It will stay fresh for up to a week! For longer storage, wash it thoroughly with soap and let it air dry.
For an average 12x10 bedroom with 8ft ceilings, expect to spend $80-150 on paint alone at typical retail prices ($25-45/gallon), plus supplies like tape, rollers, and drop cloths. Whole-house interior painting (materials + professional labor) typically runs $2-6 per square foot of wall area, varying significantly by region and paint quality.
The underlying math is the same regardless of brand — coverage is driven by square footage and paint thickness, not the label on the can. Most major brands rate their paint at 350-400 sq ft per gallon, which is what this calculator defaults to. If your specific product's can lists a different coverage rate, just update the "Paint Coverage" field above to match it exactly.
Trim and cabinets use a different rule than walls since they're measured by linear feet or piece count, not square footage. A general guide: 1 quart of trim enamel covers roughly 100-125 linear feet of standard trim (2 coats). For kitchen cabinets, budget 1 gallon of cabinet-grade enamel per 15-20 linear feet of cabinetry. For doors, 1 quart typically covers 2-3 standard doors at 2 coats each.