Garage Epoxy Kits Needed (Coats & Floor Area)
More coats mean proportionally more coverage to fill, so this multiplies floor size by coats, then divides by each kit's rated coverage.
How it works
A garage-floor epoxy kit is rated to cover a fixed area, so the math is simple: floor length times width gives the area, and area divided by the kit's coverage gives the number of kits. Rust-Oleum's EpoxyShield and RockSolid lines put a single-car kit at about 250 sq ft and a 2.5-car kit at about 500 sq ft for one coat.
Coverage is the catch. That 250 sq ft figure assumes a smooth, properly etched slab and a thin, even roll. Bare or porous concrete and a heavier film both pull the real number down, so it is worth rounding coverage down a little rather than up. If you are laying a base coat plus a clear or flake top coat, set coats to 2 — the calculator then doubles the kits.
The kit count always rounds up, because you cannot buy part of a kit and you do not want to stop mid-floor waiting on more product; epoxy has a working pot life once mixed.
floor area = 20 × 24 = 480 sq ft
kits = 480 ÷ 250 = 1.92 → 2 kits (covers ≈ 45 m²)