Short answer: a typical 2-car garage is about 400–576 sq ft. At 10 mils per coat of a 100%-solids epoxy, two coats and 15% extra for porous concrete, that's roughly 5.7–8.3 gallons. Water-based kits (lower solids) need about twice as much for the same dry thickness. Most retail kits list their coverage per coat on the box; divide your area by it.
| Floor kit | Garage floor epoxy kit → | Count kits from box coverage |
| Prep | Concrete cleaner / etcher → | Concrete cleaner/etcher |
| Flakes | Decorative floor flakes → | Optional decorative flakes |
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| Garage | Typical size | Area | Gallons (+15%) |
|---|---|---|---|
| 1-car garage | 12×22 ft | 264 sq ft | 3.8 |
| 2-car garage | 20×20 ft | 400 sq ft | 5.7 |
| 2-car garage (larger) | 24×24 ft | 576 sq ft | 8.3 |
| 3-car garage | 32×24 ft | 768 sq ft | 11.0 |
Measure your own floor; garages vary a lot. Subtract areas you won't coat, such as under fixed cabinets.
A 20×20 ft garage is 400 sq ft. Two coats is 800 sq ft of coating. At 10 mils, 100% solids covers 1,604 ÷ 10 ≈ 160 sq ft per gallon, so 800 ÷ 160 = 5 gallons, or 5.75 with 15% extra. With a kit that covers 250 sq ft per coat, 800 × 1.15 ÷ 250 = 3.7, so buy 4 kits.
More: garage floor coverage calculator (with your kit price) · how to choose a garage floor kit.
About 5–8 gallons for two 10-mil coats of 100%-solids epoxy on 400–576 sq ft, including 15% for porous concrete. Lower-solids kits need more.
Divide your area × coats × 1.15 by the coverage per coat on the kit box. Many kits are sized for a single coat on a 1-car garage, so 2-car floors often need 2–4 kits.
The base coat amount is similar, but full-flake systems usually need a topcoat over the flakes; plan for it.
More tools: resin calculator · mix ratio by weight · cure time · mold volume · tabletop coating · pouring too thick
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