Epoxy Resin Calculator

Calculate Your Epoxy Needs

Pour Shape

Measurement Unit

Length

Width

Radius

Thickness / Depth

Note: Results are estimates. Always add 5–10% extra epoxy for waste and surface absorption (this calculator's "Recommended Buy" figure already includes a 10% buffer).

What is an Epoxy Calculator?

An Epoxy Calculator is a precision digital tool designed to help DIYers, woodworkers, and contractors determine the exact volume of resin required for a specific project. Whether you are pouring a thick river table, coating a garage floor, or creating resin art, knowing the volume is the difference between a masterpiece and a sticky, unfinished mess.

Why Epoxy Calculation is Crucial

Epoxy resin is an expensive material. Underestimating the amount needed can lead to "dry spots" or visible seams if you have to mix a second batch mid-pour. Overestimating leads to expensive waste that cannot be reused once mixed. Furthermore, different projects require different pour depths, which drastically changes the volume requirements.

How to Calculate Epoxy Resin

For a rectangular pour, you need three dimensions: Length, Width, and Depth (Thickness).

The Rectangular Formula

V = L × W × D

If you are working in inches, the result is in cubic inches. Divide by 231 for gallons, or by 61.02 for liters.

Diagram of a rectangular slab labeled length, width, and depth with the formula volume equals length times width times depth — Rectangular pours: multiply the three dimensions.

The Circular Formula

For round tables, coasters, or circular molds, use the radius instead: V = π × r² × D. This calculator's "Circular" mode runs this formula automatically.

Diagram of a circular pour labeled radius and depth with the formula volume equals pi times radius squared times depth, worked example 24 inch diameter needs 0.98 gallons — Circular pours: use the radius, not the diameter, in the formula.

Epoxy for Tables, Floors, and Coatings

River Tables: These are tricky because the "river" isn't a perfect rectangle. Measure the average width of the gap and use that as your width input.
Flooring: Most floor epoxies are applied in "mils" (1/1000 of an inch). A typical 100% solids epoxy floor covers about 100 square feet per gallon at 16 mils.
Seal Coats: These are thin layers (usually 1/8") used to prevent air bubbles in wood before the main pour.

Reference chart comparing typical thickness: 16 mils for floor coatings, 1/8 inch for seal coats, 1 to 2 inches or more for deep pour river tables — How much thicker a deep pour is compared to a seal coat or floor coating.

Step-by-Step Guide to Use the Tool

Select Your Shape: Choose Rectangular or Circular.
Pick Your Unit: Inches, feet, centimeters, or meters.
Input Dimensions: Enter length and width (or radius for circular pours).
Define Thickness: Enter how deep you want the epoxy (e.g., 2 inches for a river table, 1/8 inch for a countertop).
Calculate: Hit the button to see your results in gallons, liters, and fluid ounces, plus a 10% buffer already added to the "Recommended Buy" figure.

Tips to Avoid Resin Waste

Seal Porous Surfaces: Wood absorbs resin. A thin seal coat prevents the "disappearing resin" act during your main pour.
Level Your Surface: If your table is tilted, resin pools on one side, requiring more volume to cover the "high" side.
Mix in Batches: For massive pours, calculate the total but mix in manageable increments if your resin has a short pot life.

Real-World Examples

Example 1 (Small Tray): A 12" x 12" tray with a 1/4" coating requires approximately 0.16 gallons (about 20 fl oz, or 0.59 liters).

Example 2 (River Table): A 48" x 12" (average width) river that is 2" deep requires roughly 4.99 gallons (about 18.9 liters).

Chart showing a 12 by 12 inch tray with a quarter inch coating needs 36 cubic inches, about 0.16 gallons or 20 fluid ounces — Example 1 broken down step by step.

Chart showing a 48 by 12 inch average-gap river table poured 2 inches deep needs 1152 cubic inches, about 4.99 gallons or 18.9 liters — Example 2 broken down step by step.

Reference chart: 1 US gallon equals 231 cubic inches, 1 liter equals 61.02 cubic inches, 1 US gallon equals 128 fluid ounces — The three conversion factors this calculator uses internally.

Benefits of Using Our Online Calculator

Using an online tool eliminates the risk of "math fatigue." Our tool provides instant conversions between Imperial and Metric units, includes a built-in waste margin, and is optimized for mobile use so you can calculate right in your workshop.

Rectangular & circular pours

Inches, feet, cm, or meters in

Gallons, liters & fl oz out

10% waste buffer built in

Frequently Asked Questions (FAQ)

Q: How much epoxy do I need for a table?

A: This depends on the surface area and thickness. A standard 48" x 24" table with a 1/8" decorative coating requires about 0.62 gallons.

Q: How do you calculate epoxy resin volume?

A: For a rectangular pour, multiply length × width × thickness. For a circular pour, use pi × radius squared × thickness. If measuring in inches, divide the total cubic inches by 231 to get gallons, or by 61.02 for liters.

Q: How thick should epoxy resin be?

A: For coatings, 1/8" is standard. For deep pour projects like river tables, you can go up to 1-2 inches or more depending on the resin brand's maximum safe pour depth.

Q: How much epoxy for 1 square foot?

A: At 1/8" thickness, you need approximately 10 ounces of epoxy per square foot.

Q: Can this epoxy calculator be used for river tables?

A: Yes. Use the average width of your river gap as the width input, since the gap usually isn't a perfect rectangle, for a reliable estimate.

Q: Does the calculator support metric units?

A: Yes. You can enter dimensions in inches, feet, centimeters, or meters, and results are shown in gallons, liters, and fluid ounces at once.

🧪 Pour with confidence – measure twice, mix once, waste nothing.

— accurate epoxy estimates for every maker.