Epoxy Calculator
Estimate resin volume in gallons, liters, and ounces for bar tops, river tables, flooring, and casting projects.
Plan your epoxy pour before mixing
An epoxy calculator estimates the precise volume of mixed resin and hardener required for a surface coating or deep pour. Calculate your needs by entering the length, width, and desired thickness of the project area. It is highly recommended to add a 5% to 10% waste allowance to account for spillage, mixing cup residue, and self-leveling drip-off.
The calculator provides your total mixed volume. Remember to split this total according to your specific product's mixing ratio (e.g., 1:1 or 2:1 by volume) when you begin your pour.
Total Mixed Epoxy Required
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Exactly --
Surface Area
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Length × Width.
Fluid Ounces
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Total mixed volume.
Cubic Volume
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Geometric space.
Estimated Cost
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Resin material only.
Material Checklist
Common supplies needed for a successful epoxy pour.
| Item | Purpose |
|---|---|
| Graduated Mixing Cups | Essential for measuring precise 1:1 or 2:1 ratios. |
| Stir Sticks / Paddles | For thoroughly blending resin and hardener without whipping in air. |
| Heat Gun or Butane Torch | Pops surface bubbles that rise to the top after pouring. |
| Nitrile Gloves & Plastic Tarp | Protects skin from uncured resin and floors from inevitable drips. |
Mixing note: The volume above is your total mixed amount. Always check your specific product's instructions. If it is a 1:1 ratio, divide the total volume exactly in half to know how much Part A (Resin) and Part B (Hardener) to pour.
How to use the epoxy calculator
An epoxy calculator determines how much epoxy a project requires based on surface area and pour depth. Calculate epoxy volume by multiplying length × width × depth. A 24-inch × 24-inch surface with a 0.125-inch pour depth requires 72 cubic inches of epoxy, or about 0.31 gallons.
An epoxy calculator estimates liquid resin volume, coverage, and cost for surface coatings and deep pours. Calculate epoxy by multiplying length, width, and thickness to find cubic volume, then convert cubic inches or cubic centimeters to fluid gallons or liters. Add a 10% waste factor to ensure you don't run short mid-pour.
- Measure the area: Determine the inside length and width of your mold or the surface area of your table top.
- Determine thickness: Standard flood coats are usually 1/8" (0.125 inches) thick. Deep pours for river tables can be 1" to 2" thick.
- Include a seal coat: If pouring over porous wood, check the seal coat box. This adds roughly 1 ounce per square foot to seal the wood before the main pour, preventing air bubbles.
- Include waste: Enter a percentage for mixing cup residue, spillage over the edges, and minor leveling variations. 10% is standard.
- Calculate: The calculator outputs liquid volume (Gallons/Ounces or Liters/Milliliters), which is the standard unit for buying resin kits.
Epoxy Formulas
Calculate the geometric volume of the area, apply the waste multiplier, and convert to standard liquid measurements.
Volume = Length × Width × Thickness
Order Volume = Volume × (1 + waste percentage)
1 US Gallon = 231 Cubic Inches
When calculating in Imperial units, the calculator divides cubic inches by 231 to find US Gallons, or divides by 1.80469 to find US Fluid Ounces. Metric calculations convert directly from cubic centimeters to Liters by dividing by 1,000.
Project Success Factors
Precise Ratios
Epoxy requires a perfect chemical reaction. Always measure by volume in a graduated cup (unless the brand specifies measuring by weight). Never "eyeball" the mix or add extra hardener to speed up curing.
Temperature Control
Resin works best when your workspace, the materials, and the resin itself are around 70-75°F (21-24°C). Cold resin is thick, cloudy, and traps bubbles. Hot resin can flash-cure and crack.
Thorough Mixing
Use the "two-cup method." Mix thoroughly in one cup for 3-5 minutes, scraping the sides and bottom. Pour into a second clean cup and mix for another minute to ensure unmixed resin doesn't ruin your piece.
How to Choose the Right Epoxy
Not all epoxy is the same. Selecting the right viscosity and cure speed for your specific project is critical.
| Epoxy Type | Max Pour Depth | Best Applications |
|---|---|---|
| Table Top / Flood Coat | 1/8" to 1/4" | Bar tops, tumblers, artwork coating, countertops. Cures hard and fast. |
| Deep Pour / Casting | 1" to 2"+ | River tables, large molds, turning blanks. Cures slowly to prevent overheating. |
| Flooring / Garage Resin | Very Thin (Roll-on) | Concrete garage floors, industrial surfaces. Formulated for abrasion resistance. |
| UV Resin | Thin layers | Small jewelry, fly tying, quick repairs. Cures in minutes under a UV lamp. |
Proper Epoxy Pouring: Step-by-Step
1. Surface Prep & Leveling
Ensure your surface is completely clean, dry, and dust-free. Use a level on all sides; epoxy is self-leveling, so if your table is tilted, the resin will pool on one side and drip off.
2. Apply a Seal Coat
For porous surfaces like wood, brush on a very thin layer of mixed epoxy and let it cure. This seals the wood grains and prevents massive air bubbles from releasing into your final flood coat.
3. Pour and Spread
Mix your resin and pour it evenly over the surface. Use a plastic spreader, notched trowel, or a gloved hand to guide the resin to the edges and ensure complete coverage.
4. Pop Bubbles
Wait 10-15 minutes for bubbles to rise. Briefly sweep a butane torch or heat gun 6-8 inches above the surface. The heat thins the resin, allowing the bubbles to pop instantly. Keep the heat moving!
Troubleshooting Common Epoxy Mistakes
"Fish Eyes" or Craters
Cause: Oil, grease, silicone, or dust on the substrate repelled the resin.
Solution: Ensure meticulous cleaning with denatured alcohol before pouring. If cured with fish eyes, sand the surface flat, clean, and pour a thin top coat to level it out.
Cloudiness and Micro-Bubbles
Cause: Mixing too vigorously, pouring in cold temperatures, or skipping the seal coat on porous wood.
Solution: Warm unopened resin bottles in a warm water bath before mixing. Stir slowly and smoothly, scraping sides. Always seal raw wood first.
Soft, Tacky, or Runny Spots
Cause: Inaccurate measuring (not exactly 1:1 or 2:1) or scraping unmixed resin from the sides of the cup onto your project.
Solution: Always use graduated measuring cups. Use the "two-cup method" by pouring the mixed resin into a second clean cup and mixing again before pouring.
Advanced epoxy troubleshooting and technical data: West System - Epoxy Support.
Essential Epoxy Safety and PPE
Epoxy resin is a chemical product that requires proper handling to prevent sensitization, allergic reactions, and respiratory issues.
Proper Ventilation
Always work in a well-ventilated area. If working indoors with products that emit VOCs, wear a half-face respirator equipped with organic vapor cartridges.
Skin Protection
Wear nitrile gloves (not latex) and long sleeves. Repeated skin exposure to uncured resin can cause severe contact dermatitis and long-term chemical sensitization.
Exothermic Danger
Epoxy generates heat as it cures. Never leave a large, mixed cup of epoxy unattended, as the concentrated mass can get hot enough to melt plastic cups, smoke, or even start a fire.
Occupational chemical safety and PPE guidelines: Occupational Safety and Health Administration (OSHA) - PPE.
Material Compatibility & Mold Release
| Substrate Material | Epoxy Adhesion | Prep / Application Notes |
|---|---|---|
| Wood (Live Edge, Plywood) | Excellent | Requires a thin seal coat first to prevent trapped air inside the wood grain from releasing bubbles into the main pour. |
| Concrete & Cement | Excellent | Concrete must be fully cured (28+ days), completely dry, and mechanically profiled (sanded/ground) to open the pores for adhesion. |
| Silicone & HDPE Plastics | None (Repels) | Epoxy will not stick to these materials. They are the ideal choice for creating reusable resin molds and river table forms. |
| Glass & Metal | Moderate | Requires thorough degreasing and roughing up the surface (scuff sanding) for a mechanical bond. May delaminate under temperature shifts. |
Epoxy resin chemistry and material properties: American Chemistry Council - Epoxy Resins.
Frequently Asked Questions
How much coverage do I get from 1 gallon of epoxy?
While our calculator helps you determine the exact volume needed, a general rule is that at a standard 1/8-inch thickness (typical for a tabletop or countertop flood coating), one mixed gallon of epoxy will provide a coverage of roughly 12 to 16 square feet of surface area. For metric users, one liter covers about 0.3 to 0.4 square meters. Knowing your required square footage ensures you don't overbuy and keeps your overall material cost down for the project.
What happens if I pour Table Top epoxy too thick?
Standard tabletop epoxies cure quickly and generate significant heat. If the thickness exceeds 1/4 inch, the heat gets trapped inside those cubic inches, causing the resin to "flash cure"—it will boil, smoke, turn yellow, and crack, ruining the finish. For deep mold fills or a thick river table, always use a Deep Pour casting formula designed to handle greater volume.
Why is my cured epoxy cloudy or sticky?
Sticky or soft spots are almost always the result of an inaccurate mixture ratio between the resin and the hardener, or insufficient stirring. Cloudy spots usually mean the room or the resin itself was too cold, trapping microscopic air bubbles that disrupt the clear finish.
Can I pour a new layer of epoxy over an old one?
Yes. Whether you are adding a protective coating to a floor or sealing raw wood, you can pour directly over a previous layer if it is still tacky. If the previous layer has fully cured, you must lightly sand the surface with 220-grit sandpaper and wipe away the dust to create a mechanical bond before pouring.
How long does epoxy take to cure?
The exact cure time depends on the specific formulation. Most tabletop epoxies are dry to the touch in 12 to 24 hours and fully cured in 72 hours. Deep pour epoxies cure much slower to reduce heat buildup, often taking 3 to 7 days to fully harden depending on the pour thickness and ambient temperature.
How do I color or tint my epoxy?
You can tint your mixture using mica powders, liquid epoxy dyes, or alcohol inks. Never use water-based paints or food coloring, as the moisture will ruin the chemical curing process. Add your pigments to the resin (Part A) and mix thoroughly before combining with the hardener.
Can I use epoxy for outdoor projects?
Standard epoxy resins are prone to yellowing or chalking when exposed to direct UV sunlight over long periods. If your project will remain outdoors, ensure you use a formulation specifically equipped with UV inhibitors, or apply a UV-blocking clear coat (like marine spar polyurethane) over the cured surface.
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Disclaimer: This epoxy calculator is intended for general educational, budgeting, and preliminary material-planning use only. It estimates liquid volume, coverage, and cost from user-entered measurements. It does not replace the specific mixing ratios, depth limits, or coverage rates provided by your resin manufacturer. Actual required quantities can vary based on substrate porosity, ambient temperature, complex mold shapes, leveling variations, and mixing technique. Always consult the technical data sheet (TDS) of the specific epoxy brand you are using before mixing and pouring. Furthermore, this tool does not account for the structural integrity of the finished product, the suitability of the chosen epoxy for your specific application, or the safety protocols required during application. Epoxy resins are chemicals that require appropriate personal protective equipment (PPE) and ventilation during use. Disposal of uncured resin, hardener, and mixing supplies must comply with local environmental regulations. By using this calculator, you acknowledge that the developers and publishers of this tool accept no liability for project failures, material shortages, overages, health hazards, or financial losses resulting from the use of these estimates. For the most accurate and safe results, always perform a small test pour and rely on professional guidance when necessary.
Last updated: June 12, 2026