Epoxy Floor Calculator (Gallons and Kits by Mils and Solids)
How much epoxy floor coating to buy: coverage per gallon at your dry film thickness and volume solids, gallons per coat, total with losses, and kits.
Formula
Coverage (sq ft/gal) = 1,604 × solids by volume ÷ dry mils. Gallons per coat = area ÷ coverage. Total = gallons per coat × coats × (1 + loss). Wet mils = dry mils ÷ solids.
Worked example
Inputs: Floor area = 400 sq ft; Dry film thickness per coat (from the data sheet) = 8 mils; Coats = 2; Solids by volume (from the data sheet) = 100 %; Surface and application loss = 15 %; Kit or can size = 1 gal.
| Theoretical coverage sq ft per gal | 200.5 |
|---|---|
| Wet mils per coat | 8 |
| Gallons per coat | 2 |
| Gallons total with loss | 4.59 |
| Kits to buy | 5 |
| Total dry mils | 16 |
Any liquid covers 1,604 sq ft per gallon at 1 mil; coverage at your dry film = 1,604 × volume solids ÷ dry mils. Use solids by volume from the data sheet (not by weight). Rough or porous concrete and application losses take more; Neogard suggests 5–15% for blasted concrete plus 3–10% miscellaneous loss.
FAQ
How much epoxy do I need for a 400 sq ft garage floor?
At 8 dry mils per coat with a 100% solids epoxy, one gallon covers 1,604 ÷ 8 = 200.5 sq ft, so each coat takes 2.0 gallons. Two coats plus 15% for losses is 4.6 gallons.
How many square feet does a gallon of epoxy cover?
It depends on thickness and solids: 1,604 × solids ÷ dry mils. A 100% solids epoxy at 10 mils covers about 160 sq ft per gallon; a 50% solids product at 4 dry mils covers about 200.
What does solids by volume mean?
The share of the wet coat left after solvent or water evaporates. Neogard's example: a gallon over 100 sq ft is 16 mils wet; at 50% solids by volume it dries to 8 mils. Do not use solids by weight.
Why buy more than the theoretical amount?
Theoretical coverage assumes a glass-smooth surface and no waste. Neogard suggests 5–15% more for shot-blasted concrete and 3–10% for material left in containers and equipment; up to 50% more can be needed on rough jobs.
How thick should an epoxy floor be?
Follow the product data sheet: it lists the dry mils per coat and number of coats for each use. Enter those numbers here.
Sources
Related
- Concrete Slab Calculator (Cubic Yards & Bags)
- Self-Leveling Concrete Calculator (Bags of Floor Leveler)
More Concrete calculators
- Concrete Column & Sonotube Calculator
- Concrete Footing Calculator (Continuous Wall Footings)
- Rebar Calculator for a Slab (Bars, Sticks, Lap Splices & Weight)
- Concrete Steps Calculator (Cubic Yards, Bags, Risers & Landing)
Embed this calculator
Free to embed on your site; please keep the credit link.
Last reviewed 2026-10-30.