The method

Three things most paint calculators get wrong

A square footage calculator gives you area. Buying paint needs area, coats and a real coverage rate, and a cyc needs one more step again.

Notes on the figures

Where every number comes from

Nothing here is estimated from a figure Rosco has not published.

Gallons and litres

Rosco publishes coverage per US gallon, so the headline figure is gallons. One gallon is taken as 3.79 L, the same basis the coverage figures use, and tins are listed by the size printed on them.

Why a range, not a single number

Rosco publishes a single coverage figure for some products and a range for others. On a 107 m² studio in two coats, the published Chroma Key range is the difference between roughly 7.6 and 11.2 gallons. We lead with the conservative end.

The cove arc

A quarter-circle cove has a developed length of radius multiplied by 1.57. Measured straight across the corner instead, a 1.2 m cove comes up about 0.7 m short per metre of screen width.

No prices on this page

Quantities only. Prices change, and a price copied onto a page goes stale without anyone noticing. Follow any product link for current pricing and stock.

Pack sizes

Tins are chosen for the least paint left over, without splitting an order into a handful of small tins where one pail does the job.

Supersaturated is a concentrate

Its published coverage of 8 to 10 m² per litre assumes dilution at 1:1. The quantity shown is concentrate, before water. Thinning past 5:1 can weaken the binder.

Estimate only. Real coverage moves with substrate porosity, surface texture, dilution and whether the paint is brushed, rolled or sprayed. A porous or bare surface can need an extra coat. Always test your own surface before committing to a full order. CrystalGel publishes no coverage figure, only that it varies with build thickness, so it is not in the list.