Paint Coverage Calculator Formula
Understand the math behind the paint coverage calculator. Each variable explained with a worked example.
Formulas Used
Total Coverage Needed
total_coverage_needed = area * num_coatsGallons Needed
gallons = ceil(area * num_coats / coverage_rate)Or in Quarts
quarts = ceil(area * num_coats / coverage_rate * 4)Variables
| Variable | Description | Default |
|---|---|---|
area | Paintable Area(sq ft) | 400 |
coverage_rate | Coverage Rate(sq ft/gallon) | 350 |
num_coats | Number of Coats | 2 |
How It Works
How to Calculate Paint Coverage
Formula
Gallons = (Area × Number of Coats) / Coverage Rate
Standard interior latex paint covers approximately 350-400 sq ft per gallon. Factors that reduce coverage include rough or textured surfaces, porous substrates, and dark-to-light color changes.
Worked Example
Painting 400 sq ft of wall area with 2 coats at 350 sq ft/gallon.
area = 400coverage_rate = 350num_coats = 2
- 01Total coverage = 400 × 2 = 800 sq ft
- 02Gallons = 800 / 350 = 2.29 → 3 gallons
Ready to run the numbers?
Open Paint Coverage Calculator