Ceiling Paint Calculator

Ceiling finish prep: When finishing a vaulted ceiling, we measured main surfaces with the ceiling paint calculator. But for decorative coves and angled sections, we estimated ellipse and triangle areas separately using the area calculator. That ensured our coverage estimates weren’t off by a gallon or two.

Examples

Rectangle Example (Ceiling Room)

Formula: Area = length × width

Example: If ceiling length = 15 ft and width = 12 ft, then Area = 15 × 12 = 180 ft²

Square Example (Small Ceiling)

Formula: Area = side × side

Example: If each side of the ceiling is 10 ft, then Area = 10 × 10 = 100 ft²

Circle Example (Dome Ceiling)

Formula: Area = π × radius²

Example: If radius of dome is 7 ft, then Area = π × 7² ≈ 153.94 ft²

Triangle Example (Vaulted Section)

Formula: Area = ½ × base × height

Example: If vaulted section has base = 10 ft and height = 6 ft, then Area = ½ × 10 × 6 = 30 ft²

Paint Estimation

Assume 1 gallon of paint covers 350 ft². For a 180 ft² ceiling, you’ll need 180 ÷ 350 ≈ 0.51 gallons, or 1 gallon rounded up.

This ceiling paint calculator estimates the surface area of various ceiling layouts, including flat ceilings, vaulted ceilings, tray ceilings, cathedral ceilings, and circular ceilings. Formulas are provided below.

Flat Ceiling
The area of a flat ceiling is A = length × width, where both are measured in horizontal plane. For a room 14 ft long and 12 ft wide, the calculator gives A = 14 × 12 = 168 ft².

Vaulted Ceiling
For a vaulted ceiling modeled as two sloped rectangles, calculate A = 2 × (slope length × room width). For slope length = 10 ft and width = 12 ft, the calculator returns A = 2 × 10 × 12 = 240 ft².

Tray Ceiling
A tray ceiling has a recessed inner portion; total area is A = outer rectangle + inner recess. If outer = 16 × 14 ft and inner = 10 × 8 ft, the calculator computes A = (16 × 14) + (10 × 8) = 224 + 80 = 304 ft².

Cathedral Ceiling
The area of a cathedral ceiling is calculated as two congruent triangles: A = 2 × ½ × base × height = base × height. For a ceiling 20 ft wide and 6 ft high at the center, A = 20 × 6 = 120 ft².

Circular Ceiling
A circular ceiling area is A = π × radius². For a radius of 10 ft, the ceiling paint calculator gives A = π × 10² = π × 100 ≈ 314.16 ft².