Paint coverage
Estimate paint for walls and ceilings, accounting for openings, coats and waste. Drag the graph handles to change inputs and explore the result.
Your inputs
The editable example is illustrative. Enter your own dimensions, operating data, prices, and fees. Results update as you edit.
Calculations run in your browser. Inputs are not saved or sent to analytics.
How it works
- Net area = Σ ( × − ); Paint needed = Area × ÷ × (1+/100); Whole containers = ceil(Paint needed/)
- Worked example: 40 m² × 2 ÷ 10 m²/L × 1.1 = 8.8 L; ceil(8.8/5) = 2
- Supported input limits: Entries: 1–21; : 1 ≤ x ≤ 100; : 1e-12 ≤ x ≤ 1,000,000,000,000; : 0 ≤ x ≤ 1,000; : 1e-12 ≤ x ≤ 1,000,000,000,000
Input and formula key
Your result
Complete the inputs to see your result.
Assumptions and limitations
Surface dimensions use the chosen length unit, but openings are always m². Coverage is m² per chosen paint-volume unit per coat. Container counts round up; texture, absorption and product-specific coverage must be reflected in your inputs.
Sources
- NIST — conversion factor conventions Sources reviewed: 2026-10-06
- NIST — conversion factor table B.8 Sources reviewed: 2026-10-06
- OpenStax — rectangle areas and dimensional measures Sources reviewed: 2026-10-06
