Paint requirement

Four walls of a rectangular room: 2 × (length + width) × height. Optionally add the ceiling. Door and window areas are deducted from the walls only. Counts share the dimensions entered in each group; add equivalent dimensions for unequal openings. Deductions cannot exceed the wall area.

For each product separately: litres = paintable area × coats / coverage × (1 + reserve/100). Containers are rounded up independently. Use the actual manufacturer coverage per coat and container size. Paint and primer may have different coverage and sizes. Defaults are examples; reserve is your allowance, not a measured loss.

Optional price is per paint container. Paint cost includes complete paint containers only, excluding primer, taxes and delivery. Currency is a display choice, without exchange-rate conversion.

Calculate or Enter; edits hide old results. Reset restores defaults. Dimensions, coverage and container sizes: 0.000001–1000000 in the stated unit; opening counts: 0–1000000; coats: 1–100; reserve: 0–100%; price: 0–1000000000. Software limits. No recommendations for products, preparation, coats or surface suitability; no input storage.