Coatings & Adhesives
Epoxy Calculator
Last Updated On
Calculate epoxy quantities for floor coating systems (primer, base coat, topcoat), self-leveling epoxy floors, and anchor bolt / rebar installations. Get exact Part A and Part B volumes, kit counts, and cartridges — in metric (litres) or imperial (US quarts).
Epoxy Calculator
Floor coating, self-leveling & anchor bolt epoxy
Application Type
Coverage Rate
Mix Ratio (Part A : Part B)
Results
Total Mixed Volume
42.24 qt
Part A Required
28.16 qt
Part A per kit
1.00 gal
× 8 kits
Coverage rate
150 ft²/gal
Standard base coat
Always read the product TDS for exact coverage rates — porosity, temperature, and substrate condition significantly affect consumption. Order 10–15% extra for first-time applications.
Step-by-Step Calculation
Step 1 — Area
30.00 × 24.00 = 720.00 ft²
Step 2 — Epoxy for 2 coats (Standard base coat)
720.00 ft² ÷ 150 ft²/gal × 2 = 9.60 gal
× (1 + 10.0% waste) = 10.56 gal
Step 3 — Split by mix ratio 2:1
Part A = 10.56 gal × 2/3 = 7.04 gal
Part B = 10.56 gal × 1/3 = 3.52 gal
Step 4 — Kits
A: 7.04 gal ÷ 1.00 gal = 7.04 · B: 3.52 gal ÷ 0.50 gal = 7.04
round the larger up → 8 kits
Result — 10.56 gal mixed epoxy, 8 kits
Epoxy Floor Layer System
A typical 3-coat epoxy floor system: primer penetrates the concrete, the base coat builds colour and thickness, and the topcoat provides chemical and abrasion resistance.
How the Calculator Works
1. Floor Coating Volume
Divide the floor area by the product's coverage rate (from the Technical Data Sheet), multiply by the number of coats, then add your waste factor. Coverage rates vary widely: a primer is typically 5–6 m²/L (200–250 ft²/gal) while a heavy-build intermediate coat may only cover 2.5 m²/L (100 ft²/gal). Always use the TDS rate for your specific product — porous or rough concrete can consume 20–30% more.
2. Self-Leveling Epoxy Volume
Self-leveling systems are specified by pour thickness, typically 2–6 mm. Volume is simply area × thickness — 1 litre covers exactly 1 m² at 1 mm depth. A 3 mm pour over 80 m² needs 240 litres of mixed epoxy. Account for 10–15% extra for floor flatness variation, puddles at low spots, and waste in hoses and buckets.
3. Part A and Part B Split
Two-part epoxy must be mixed in the exact ratio specified by the manufacturer — typically 2:1 or 3:1 by volume (Part A resin to Part B hardener). Incorrect ratios cause soft spots, poor adhesion, or failure to cure. Always mix complete kits — partial mixes are difficult to ratio accurately. Kits needed = ceil(Part A required ÷ Part A kit size).
4. Epoxy Anchor Bolt Volume
When setting anchor bolts in drilled holes, the bolt itself displaces approximately 45% of the hole volume for a standard round hole and bolt. The fill factor of 0.55 accounts for this. Cartridge epoxy systems (300–600 mL) include a mixing nozzle — always waste one full nozzle volume before injection. Select the cartridge size closest to your total volume to minimize waste.
Typical Coverage Rates by System
| System / Coat | m²/L | ft²/gal | Notes |
|---|---|---|---|
| Primer / penetrating sealer | 5–6 | 200–250 | Thin coat; porous concrete uses more |
| Standard base coat (100 µm DFT) | 3.5–4 | 140–160 | Most common for colour coats |
| Heavy-build intermediate coat | 2–2.5 | 80–100 | Broadcast systems; textured floors |
| Topcoat / UV-stable sealer | 6–8 | 250–320 | Thin; multiple coats recommended |
| Self-leveling 2 mm | 0.5 | 20 | 1 L = 1 m² at 1 mm depth |
| Self-leveling 3 mm | 0.33 | 13.5 | Standard decorative pour |
| Self-leveling 6 mm | 0.17 | 6.7 | Heavy industrial |
Worked Example
Warehouse floor: 30 m × 20 m = 600 m², 2-coat system (primer + base coat), 2:1 mix ratio, 5 L Part A kits, 10% waste.
Film Thickness Drives Everything
Epoxy is bought by volume and applied by thickness, so small changes in depth have large effects on cost:
- Thickness Is a Linear Multiplier: Doubling the film from 10 to 20 mils exactly doubles the material. Knowing the target thickness before ordering is what makes an epoxy budget predictable.
- Correct A:B Ratio Is Non-Negotiable: Epoxy cures by chemical reaction, not evaporation. Off-ratio mixing leaves a permanently soft or tacky floor that has to be ground off, so Part A and Part B quantities must both be right.
- Pot Life Limits Batch Size: Mixed epoxy begins curing immediately and generates its own heat in the pail. Mixing more than can be spread inside the pot life means it kicks off before it reaches the floor.
Example Calculations
Three scenarios worked through step by step:
Example 1 — Garage Floor Coating
Floor 24 ft × 24 ft, 10 mil film, 10% waste.
Area = 24 × 24 = 576 ft²
Coverage at 10 mil ≈ 160 ft² per gallon
Epoxy = 576 ÷ 160 = 3.6 gallons
With 10% waste = 3.96 → 4 gallons
At 2:1 ratio = 2.67 gal Part A + 1.33 gal Part B
Example 2 — Self-Levelling Pour
Room 15 ft × 12 ft at 1/8 in depth, 10% waste.
Area = 15 × 12 = 180 ft²
Depth = 0.125 ÷ 12 = 0.01042 ft
Volume = 180 × 0.01042 = 1.875 ft³
Gallons = 1.875 × 7.481 = 14.03 gal
With 10% waste = 15.4 → 16 gallons
Example 3 — Anchor Bolts
20 bolts, 3/4 in bolt in a 1 in hole, 8 in embedment.
Hole radius = 0.5 in; bolt radius = 0.375 in
Annulus area = π × (0.5² − 0.375²) = 0.3436 in²
Volume per bolt = 0.3436 × 8 = 2.75 in³
Total = 2.75 × 20 = 55 in³
Result: about 2 standard 28 oz adhesive cartridges
Application Tip
Application Tip
Mix only what you can spread within the pot life, and never leave mixed epoxy sitting in the pail. The reaction is exothermic, so a full pail heats itself, accelerates, and can kick off in minutes — pour it out onto the floor immediately after mixing, where the thin film sheds heat and gives you the full working window.
Frequently Asked Questions
- How do I calculate how much epoxy floor coating I need?
- Divide your floor area by the product coverage rate (in m²/L or ft²/gal from the TDS), multiply by the number of coats, and add 10% waste. For example, 80 m² at 3.7 m²/L with 2 coats = (80 ÷ 3.7) × 2 × 1.10 = 47.6 litres of mixed epoxy.
- What is the standard epoxy mix ratio?
- 2:1 by volume (2 parts resin to 1 part hardener) is the most common ratio for commercial epoxy floor coatings. Self-leveling systems often use 3:1 or 4:1. Anchor bolt cartridge epoxies are typically pre-metered at 1:1 or 2:1 by the nozzle. Always follow the product TDS — incorrect ratios cause incomplete cure.
- How thick should a self-leveling epoxy floor be?
- Decorative self-leveling epoxy is typically poured at 2–3 mm for light commercial use (offices, showrooms) and 4–6 mm for heavy commercial or industrial floors. A 3 mm pour on 100 m² requires 300 litres of mixed epoxy. Broadcast systems with aggregate can go thicker, up to 9–12 mm.
- How much epoxy do I need for anchor bolts?
- Calculate the hole volume (π × r² × embedment depth), then multiply by 0.55 to account for the bolt displacing ~45% of the hole. Add 10% waste for nozzle purge and spills. A 16 mm hole drilled 150 mm deep needs approximately 16.6 mL of epoxy per bolt.
- How much epoxy do I need per square foot?
- At the common 10 mil roll-on thickness, one gallon covers about 160 ft². A 1/8 in self-levelling pour is roughly twelve times thicker, covering only about 12 ft² per gallon. Thickness, not area, is what dominates the quantity.
- What is a mil and how does it relate to inches?
- A mil is one thousandth of an inch. A 10 mil coating is 0.010 in thick, and 1/8 in equals 125 mils. Coating data sheets almost always quote coverage in mils, so converting is the first step in any epoxy estimate.
- What happens if I get the mix ratio wrong?
- The epoxy will not cure properly. Too much hardener or too much resin leaves a floor that stays soft, tacky, or rubbery indefinitely, and the only remedy is mechanical removal. Measure by the stated ratio, and mix by volume or weight exactly as the data sheet specifies.
- Do I need to prepare the concrete first?
- Yes, and this matters more than the product choice. Concrete must be mechanically profiled by grinding or shot blasting, free of sealers and curing compounds, and dry. Epoxy over unprepared or sealed slab delaminates in sheets.
- How do I check if my slab is dry enough?
- Tape a 2 ft square of plastic sheet to the floor and leave it 24 hours — condensation underneath means too much moisture. For a proper assessment use a calcium chloride test or in-situ relative humidity probes, which most manufacturers require above certain limits.