You'll need
2 gal + 1 qt
Cost
$72–$185
Project details
Room dimensions
Doors
Windows
Surface
Standard interior walls
Paint
Shopping list
Everything you need to buy for this project.
- Interior Eggshell paint, 1-gallon2 cans
- Interior Eggshell paint, 1-quart1 can
- Roller covers (3/8" nap)2
- Angled brush (2½")1
- Painter's tape (1.88" × 60yd)2 rolls
- Drop cloth (9' × 12')1
Ready to buy?
Compare paint brands and pick up your gallons today at Home Depot.
Math breakdown
Step-by-step from your inputs to the can recommendation.
Wall area · 2 × (14 + 12) × 8416 sq ft
Doors · 1 × 21 sq ft−21 sq ft
Windows · 2 × 15 sq ft−30 sq ft
Net paintable area365 sq ft
Effective coverage · Interior Eggshell on Smooth, primed375 sq ft / gal
Coats × paintable730 sq ft total
Gallons before waste1.95 gal
With 10% waste factor2.14 gal
Smart split → 2.25 gal capacity2 gal + 1 qt
How to use this calculator
Measure each wall you plan to paint. Multiply the room's perimeter by the ceiling height to get total wall area, then subtract space for doors and windows. Choose your paint type — eggshell and matte cover more area than semi-gloss. Going from a dark color to a light one? Plan on 2–3 coats.
Pro tips
Buy a little extra.Running out mid-project means another store trip and possibly a slightly different shade. Our calculator already adds 10% waste — don't skip it.
Primer matters. Painting over a dramatically different color, fresh drywall, or a glossy surface? Plan to prime first. Primer covers 200–300 sq ft per gallon.
Buy gallons, not quarts. A gallon is almost always cheaper per ounce. Reserve quarts for trim or small accents.
Frequently asked questions
How much does 1 gallon of paint cover?▾
A standard gallon of interior latex paint covers about 350–400 square feet with one coat, depending on the finish and surface. Flat and matte cover the most; semi-gloss covers the least.
Do I really need two coats?▾
Most painted-over surfaces need two coats for a uniform finish. One coat may be enough if you're painting a similar color over an existing finish, or if you used a tinted primer.
What's the difference between flat, eggshell, and semi-gloss?▾
Flat hides imperfections best but isn't washable. Eggshell is the all-purpose choice for living spaces. Semi-gloss is for trim, doors, kitchens, and bathrooms — wipeable and moisture-resistant.
How long does interior paint take to dry?▾
Most latex paints are dry to the touch in 1 hour and ready to recoat in 4 hours. Fully cured takes about 30 days.
Can I store leftover paint?▾
Yes. Seal the can tightly and store indoors away from temperature extremes. Properly stored latex paint stays usable for 2–10 years.
Disclaimer. This calculator provides estimates for planning purposes. Actual material quantities and costs may vary based on site conditions, material availability, and local pricing. Always consult a licensed contractor for precise project quotes.