How this floor coating calculator works
Epoxy floor coatings are specified by film thickness in mils (thousandths of an inch) or millimeters. The calculator converts your floor area and target thickness into liquid volume: one gallon of 100%-solids epoxy covers about 1,600 square feet at 1 mil, so a 10 mil coat covers about 160 sq ft per gallon (about 4 m² per liter at 0.25 mm). Water-based products contain solvents that evaporate, so their coverage per gallon is lower at the same dry thickness — check the label.
How thick should a garage floor coating be?
A single decorative coat is 8–12 mils (0.2–0.3 mm). A durable two-coat garage system — primer plus body coat — lands around 20 mils total, and heavy-duty or flake-broadcast systems run 30 mils (0.75 mm) or more. Thicker isn't automatically better: follow the manufacturer's recoat window and maximum per-coat thickness.
Surface prep decides everything
Epoxy fails from the concrete up, not from wear down. The slab must be clean, dry and profiled — etched with acid or, better, mechanically ground. New concrete needs 28 days of cure, and a moisture test (tape a plastic square down for 24 hours; condensation underneath means too damp) saves you from peeling coats later.
Don't forget the extras
Add a primer coat for bare concrete (thinner, so roughly half the body-coat volume), anti-slip additive for the top coat, and 10% extra if your floor is rough or porous — the first coat soaks in. Color flakes take about 1 lb per 25 sq ft (0.2 kg/m²) for partial broadcast.