Paint Calculator FAQ
Expert answers to the most common paint calculation questions.
How much paint do I need for a 10x10 room?
For a 10x10 room with standard 8-foot ceilings, you'll need approximately 1.5 gallons for 2 coats. The wall area is 320 sq ft, minus a standard door and window leaves about 285 sq ft. At 375 sq ft/gallon coverage for 2 coats: (285 × 2) ÷ 375 = 1.52 gallons.
How much paint do I need for a 12x12 room?
A 12x12 room with 8-foot ceilings requires about 2 gallons for 2 coats. Wall area is 384 sq ft, minus door and window is 349 sq ft. Calculation: (349 × 2) ÷ 375 = 1.86 gallons, round up to 2 gallons.
Do I need to paint the ceiling?
It depends on your project. Ceilings are typically painted with flat/matte paint. A 12x12 ceiling is 144 sq ft and requires about 0.5 gallons. If your ceiling needs painting, calculate it separately using 400-450 sq ft/gallon coverage.
How many coats of paint should I apply?
Most projects require 2 coats for even coverage and color depth. Primer may need 1 coat. Dramatic color changes (light to dark or dark to light) often need 2-3 coats. High-gloss finishes typically require 2-3 coats.
What is the coverage rate for different paint types?
Coverage varies by paint type: Flat/Matte (400-450 sq ft/gal), Eggshell/Satin (350-400 sq ft/gal), Semi-Gloss (350-400 sq ft/gal), High-Gloss (300-350 sq ft/gal), Primer (300-400 sq ft/gal), Exterior (250-350 sq ft/gal).
Should I account for doors and windows?
Yes, subtract openings from your wall area. Standard door is 20 sq ft, standard window is 15 sq ft, large window is 35 sq ft. This prevents overbuying paint and gives more accurate estimates.
How do I calculate paint for trim and baseboards?
Measure the linear feet of trim and multiply by the height. Most baseboards are 6-8 inches tall. For example, 100 linear feet of 6-inch baseboard is 50 sq ft. Use semi-gloss or high-gloss paint with 350-400 sq ft/gallon coverage.
Does texture affect how much paint I need?
Yes, textured or porous surfaces absorb more paint. Rough surfaces like stucco or brick may use 20-30% more paint. Raw wood or new drywall also absorbs more. Always prime porous surfaces first for better coverage.