Paint measurement, coats & label inputs
Count coated surface area first, then use the coverage on the paint you chose to plan cans.
A room’s floor area is not its paintable wall area. Keep surfaces, coats and product coverage separate so a change of color, finish or surface does not silently reuse the wrong quantity.
Measure what receives paint
Walls use perimeter times height, minus measured openings. Ceilings use floor-plan area. Doors, trim, cabinets and exterior gables need their own measured surfaces or separate lists.
Choose coats explicitly
Coats multiply the same paintable area. Primer is a separate choice with its own coverage and container size. The calculator does not decide whether a coating or primer is suitable.
Use the correct coverage value
Read coverage for the selected coating and intended surface/application. If the label gives a range, try both ends as scenarios; do not present the more optimistic end as a guarantee.
Keep colors and finishes separate
Rooms sharing a product can combine before can rounding. Different finishes or colors cannot share the same can allowance. Record repairs, access and protection separately from paint quantity.
See the measurement become an order
Example: a 12 × 10 ft room with 8 ft walls and 44 sq ft of openings, two coats and an editable 400 sq ft per gallon coverage.
This example gives 2 1-gallon paint cans.
- Surface area: 308 sq ft
- ceil(308 × 2 × (1 + 0/100) ÷ 400) = 2