Epoxy Coverage Calculator
Calculate epoxy floor coating needed. Determine gallons required for primer and topcoat.
Coverage Calculation
Getting Epoxy Coverage Right
Two-part epoxy floor coating at 10 mils covers about 160 sqft per gallon. Plan for two coats minimum—one coat looks thin and shows roller marks. That's your baseline. A standard garage (500 sqft) at 10 mils per coat needs 3-4 gallons per coat. Skip the primer and the topcoat peels off in six months. Use Rust-Oleum EpoxyShield or similar, follow the instructions, and don't try to get cute with application.
The Three-Step Epoxy System
- Primer (3-5 mils): Bonds to concrete, blocks moisture, makes the topcoat stick. Non-negotiable.
- Single Topcoat (8-10 mils): Better than nothing but shows everything. Best for light residential.
- Double Topcoat (16-20 mils total with primer): What garages and basements need. Lasts longer, handles traffic.
Coverage Math by Thickness
| Thickness | Mils | Sq Ft/Gallon | Good For |
|---|---|---|---|
| Thin primer | 3 | ~500 sqft | Making topcoat stick |
| Standard finish | 10 | ~160 sqft | Most residential |
| Heavy duty | 20 | ~80 sqft | Shops, high traffic |
| Pool areas | 15 | ~107 sqft | Wet environment |
Prep Work Is Everything
Concrete has to be ground or shot-blasted—no exceptions. Fill cracks. Run a moisture test (serious). Clean until it's spotless. Epoxy sticks to clean, prepared concrete. It doesn't stick to dusty, poorly prepped surfaces. This is where 80% of failures come from. Don't rush it.
