Estimate epoxy resin and hardener quantity, coverage, and cost for your project
Built with EpoxyWise
Founder & CEO, Toolraxy
Faiq Ur Rahman is a web designer, digital product developer, and founder of Toolraxy, a growing platform of web-based calculators and utility tools. He specializes in building structured, user-friendly tools focused on health, finance, productivity, and everyday problem-solving.
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Epoxy projects whether you are coating a garage floor, sealing a bar top, or creating resin art require precise mixing ratios and accurate coverage calculations to succeed. An Epoxy Calculator helps you determine how much epoxy you need based on your surface area, coating thickness, and the number of coats you plan to apply. Beyond quantity, the tool also shows the correct resin-to-hardener ratio for your epoxy type, calculates material costs, and adds a 15% allowance for mixing tools and supplies. Whether you are a DIY enthusiast tackling your first epoxy project or a professional contractor quoting a large job, Toolraxy provides a free, client-side calculator that takes the guesswork out of epoxy estimation.
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Select your preferred currency from the dropdown at the top of the tool.
Enter the length and width of your surface in feet.
Choose your coating thickness: 3, 5, 8, or 12 mils.
Select your epoxy type: Standard 1:1, Clear/Bar Top 2:1, or Industrial 4:1.
Enter the coverage rate from your epoxy product label in square feet per gallon per mil.
Enter the epoxy kit price per gallon.
Select the number of coats you plan to apply.
Click Calculate. The tool displays surface area, coverage per gallon at your thickness, epoxy needed in gallons, resin-to-hardener ratio, material cost, supplies cost, and total estimated project cost.
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This Epoxy Calculator uses surface area, coating thickness, and coverage rate to determine the required epoxy volume, then applies cost factors.
Surface Area Calculation:
Surface Area = Length ร Width
Coverage Calculation:
The coverage rate entered is stated in square feet per gallon per mil of thickness. The actual coverage at your selected thickness is:
Coverage per Gallon = Base Coverage รท Thickness in mils
For example, a product rated at 1,600 sq ft per gallon per mil would cover 1,600 รท 5 = 320 sq ft per gallon at 5 mils thickness.
Epoxy Quantity Calculation:
Gallons Needed = (Surface Area รท Coverage per Gallon) ร Number of Coats
Gallons Rounded Up = Ceiling of Gallons Needed
Resin-to-Hardener Ratios:
Three epoxy types are supported, each with a different mixing ratio:
Standard: 1 part resin to 1 part hardener (1:1)
Clear/Bar Top: 2 parts resin to 1 part hardener (2:1)
Industrial: 4 parts resin to 1 part hardener (4:1)
The ratio affects how you mix the components but does not change the total volume calculation. The calculator displays the correct ratio for your selected epoxy type.
Cost Calculations:
Material Cost = Gallons Rounded Up ร Price per Gallon
Supplies Cost = Material Cost ร 0.15
Total Cost = Material Cost + Supplies Cost
The 15% supplies allowance covers mixing containers, stir sticks, rollers, squeegees, tape, and protective gloves.
Currency Conversion:
All costs are calculated in USD and converted to the selected currency using built-in exchange rates. Currencies without decimal usage (JPY, KRW, VND, INR) are rounded to whole numbers.
Coverage Efficiency Assessment:
The calculator classifies efficiency by dividing surface area by gallons needed: below 50 sq ft per gallon is high consumption, 50โ120 is moderate, and above 120 is efficient. This reflects coating thickness and number of coats.
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Consider a homeowner coating a 12 ft ร 10 ft bar top with clear epoxy at 5 mils thickness, 2 coats, coverage at 1,600 sq ft per gallon per mil, priced at $85 per gallon:
Surface area: 12 ร 10 = 120 sq ft.
Coverage at 5 mils: 1,600 รท 5 = 320 sq ft per gallon.
Epoxy needed: (120 รท 320) ร 2 coats = 0.75 gallons.
Rounded up: 1 gallon.
Ratio: Clear/Bar Top = 2:1 resin to hardener.
Material cost: 1 ร $85 = $85.
Supplies: $85 ร 0.15 = $12.75.
Total cost: $85 + $12.75 = $97.75.
Coverage efficiency: 120 รท 1 = 120 sq ft per gallon, classified as “Efficient coverage.”
If the same surface used industrial epoxy at 12 mils thickness with 3 coats, the calculation changes: coverage at 12 mils is 1,600 รท 12 = 133 sq ft per gallon, total needed is (120 รท 133) ร 3 = 2.7 gallons, rounded up to 3 gallons. At $95 per gallon, the total cost including supplies would be approximately $328. This example shows how thickness and coat countโnot just areaโdrive epoxy consumption.
How accurate is this epoxy calculator?
The calculator applies standard surface area and coverage formulas. Accuracy depends on the coverage rate you enter from your specific epoxy product. Always check the product label. Actual coverage varies with surface porosity, application technique, and temperature.
Why does coating thickness matter so much?
Epoxy coverage is inversely proportional to thickness. Doubling the thickness cuts the coverage area in half. A 5-mil coating covers half the area of a 2.5-mil coating from the same gallon. Accurate thickness selection prevents both under-ordering and waste.
Can I use this calculator for deep-pour epoxy?
This calculator is designed for coating applications up to 12 mils. Deep-pour epoxy for river tables or encapsulation uses different formulations measured in fractions of an inch, not mils. For deep pours, consult the manufacturer’s specific pour-depth guidelines.
What is the difference between resin and hardener in the calculation?
The calculation determines total mixed epoxy volumeโresin plus hardener combined. The ratio tells you how to split that volume. In a 2:1 epoxy, two-thirds of the total is resin and one-third is hardener. The calculator displays this ratio but calculates the total combined amount.
How do I convert mils to inches?
One mil is 0.001 inches. 5 mils = 0.005 inches. 12 mils = 0.012 inches. The calculator uses mils directly, matching how most epoxy product labels state coverage rates.
Does the calculator account for surface porosity?
No. Porous surfaces like unsealed concrete or wood absorb more epoxy and reduce effective coverage. If your surface is porous, enter a more conservative coverage rate or apply a seal coat first.
Does the calculator store my project data?
No. All calculations run entirely in your browser. No personal or project data is saved or transmitted.
Can I share my epoxy estimate?
Yes. Use the Copy button to copy all results, or the Share button to send a summary that includes your epoxy quantity and total cost.
Is this calculator a substitute for professional advice?
No. This tool provides estimates for planning purposes. For complex projects, structural applications, or professional installations, consult a qualified contractor or the epoxy manufacturer’s technical support.
What temperature is best for epoxy application?
Most epoxies cure best between 70โ85ยฐF. Cold temperatures slow curing and can prevent proper bonding. High temperatures accelerate curing, reducing working time. Always follow the manufacturer’s temperature recommendations for your specific product.
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