Paint for 18,377 sq ft
For 18,377 square feet you need approximately 105.01 gallons (397.5 liters) of paint (2 coats). Free paint calculator.
Coverage: 350 sq ft per gallon per coat. 18,377 sq ft x 2 coats / 350 = 105.01 gallons ≈ 397.47 liters.
How This Was Calculated
Wall Area = 2 x (Length + Width) x Height
Net Area = Wall Area + Ceiling - (Doors x 21 + Windows x 15)
Gallons = (Net Area x Coats) / 350
One gallon of paint typically covers about 350 square feet per coat (one liter covers about 8.6 square meters). Textured walls, dark-to-light color changes, and unprimed surfaces may need 10-20% more.
Quick Reference Table
| Input | Result |
|---|---|
| 18372 | 104.98 gallons (397.4 liters) |
| 18375 | 105.00 gallons (397.4 liters) |
| 18376 | 105.01 gallons (397.4 liters) |
| 18378 | 105.02 gallons (397.5 liters) |
| 18379 | 105.02 gallons (397.5 liters) |
| 18382 | 105.04 gallons (397.6 liters) |
Frequently Asked Questions
How much paint do I need for a 12x12 room?
A 12 x 12 ft room with 9 ft walls, one door, and one window needs about 2.3 gallons (8.8 liters) for two coats on the walls. Add the ceiling and you need about 3 gallons.
How much area does one gallon of paint cover?
One gallon covers approximately 350 square feet per coat on smooth, primed walls. Rough or textured surfaces may only get 250-300 sq ft per gallon.
Should I buy extra paint?
Yes — buy 10% extra for touch-ups and future repairs. Rounding up to the next full gallon is standard practice. Leftover paint keeps for years if sealed properly.
Do I always need two coats?
Two coats give the best color depth and durability. One coat may suffice when repainting a similar color over primed walls. Dramatic color changes (dark to light) may need primer plus two coats.
How do I measure an odd-shaped room?
Break the room into rectangular sections, calculate each wall separately, then add them together. For sloped ceilings, measure the wall at its average height.