Epoxy Resin Calculator

Calculate the exact amount of epoxy resin required for your river table, bar top, or casting mold. Computes total volume and precise Part A / Part B mix ratios.

Project Shape

Length inches Please enter a valid length

Width inches Please enter a valid width

Diameter inches Please enter a valid diameter

Pour Depth inches e.g. 0.125 for 1/8" flood coat Please enter a valid depth

Mix Ratio (By Volume)

Check your manufacturer's instructions.

Edge Treatment

Flowing over edges requires ~15% more resin.

Waste buffer %

Accounts for residue left in mixing cups. Please enter a valid percentage

Calculation Results

Total Mixed Epoxy Needed

— fl oz

—

Mixing Ratio Breakdown

How to use this epoxy calculator

Enter your project dimensions

Select whether your mold or table is rectangular or circular, then input the measurements in inches.

Specify the pour depth

A standard "flood coat" for a bar top is usually 1/8" (0.125 inches) thick. A "seal coat" brushed on beforehand is typically 1/16" (0.062 inches). Deep pour casting epoxy can range from 1 to 4 inches deep depending on the brand.

Set your mix ratio and edges

Tabletop epoxies are almost universally mixed at a 1:1 ratio by volume. Deep pour epoxies often use a 2:1 ratio. If your tabletop does not have a raised lip (a dam) and you intend to let the epoxy self-level by flowing over the edges, select "Flow Over" to add a mandatory 15% volume buffer.

Read the mix breakdown

The tool outputs the total U.S. Fluid Ounces (and Gallons) required. Most importantly, the chart visualizes exactly how many ounces of Part A (Resin) and Part B (Hardener) you need to pour into your mixing buckets.

Epoxy Resin Coverage Matrix (Includes 15% Edge/Waste Allowance)

Surface Area	Pour Depth	Total Ounces	Total Gallons Needed
10 sq ft	1/8 inch (Seal)	115 oz	0.9 Gal
10 sq ft	1/4 inch (Flood)	230 oz	1.8 Gal
10 sq ft	1/2 inch (Deep)	459 oz	3.6 Gal
10 sq ft	1 inch (Casting)	918 oz	7.2 Gal
20 sq ft	1/8 inch (Seal)	230 oz	1.8 Gal
20 sq ft	1/4 inch (Flood)	459 oz	3.6 Gal
20 sq ft	1/2 inch (Deep)	918 oz	7.2 Gal
20 sq ft	1 inch (Casting)	1835 oz	14.3 Gal
30 sq ft	1/8 inch (Seal)	345 oz	2.7 Gal
30 sq ft	1/4 inch (Flood)	689 oz	5.4 Gal
30 sq ft	1/2 inch (Deep)	1377 oz	10.8 Gal
30 sq ft	1 inch (Casting)	2753 oz	21.5 Gal
40 sq ft	1/8 inch (Seal)	459 oz	3.6 Gal
40 sq ft	1/4 inch (Flood)	918 oz	7.2 Gal
40 sq ft	1/2 inch (Deep)	1835 oz	14.3 Gal
40 sq ft	1 inch (Casting)	3670 oz	28.7 Gal
50 sq ft	1/8 inch (Seal)	574 oz	4.5 Gal
50 sq ft	1/4 inch (Flood)	1147 oz	9.0 Gal
50 sq ft	1/2 inch (Deep)	2294 oz	17.9 Gal
50 sq ft	1 inch (Casting)	4588 oz	35.8 Gal
100 sq ft	1/8 inch (Seal)	1147 oz	9.0 Gal
100 sq ft	1/4 inch (Flood)	2294 oz	17.9 Gal
100 sq ft	1/2 inch (Deep)	4588 oz	35.8 Gal
100 sq ft	1 inch (Casting)	9175 oz	71.7 Gal

Frequently asked questions

How do you calculate epoxy coverage?

To calculate coverage by volume, you multiply the length, width, and depth of your project in inches to find the Cubic Inches. Because 1 cubic inch is equal to 1.805 U.S. Fluid Ounces, you divide the cubic inches by 1.805 to determine exactly how many ounces of mixed epoxy you need.

Should I mix epoxy by weight or by volume?

Always mix according to the manufacturer's specific instructions. However, the vast majority of consumer epoxies are formulated to be mixed by volume. Mixing by weight is risky unless the manufacturer provides specific weight ratios, because Part A (resin) and Part B (hardener) have different physical densities (Part A is usually heavier).

What is a seal coat and do I need one?

A seal coat is a very thin layer of epoxy (about 1/16" thick) brushed over a porous surface like raw wood before the main flood coat. Wood contains air; if you pour a thick flood coat directly onto raw wood, the air will escape as bubbles and become trapped in your finish. The seal coat locks the air inside the wood first.

How much epoxy do I lose if it flows over the edges?

If your table does not have a physical dam or molding to contain the liquid, you should calculate an additional 15% volume to account for the epoxy that will flow over the sides and drip off the bottom to ensure a level, seamless self-leveling finish.

About this calculator

This epoxy calculator is built for woodworkers, resin artists, and DIY countertop builders. Epoxy is incredibly expensive, and running short halfway through a pour will ruin a project, as a second batch cannot be mixed fast enough to prevent a visible seam.

The calculations utilize precise volumetric conversions:

Rectangular Volume = L × W × Depth (Cubic Inches)
Circular Volume = π × Radius² × Depth (Cubic Inches)

Base Fluid Ounces = Cubic Inches ÷ 1.805
Total Ounces = Base Ounces × Edge Penalty (1.15) × Waste Factor

Gallons = Total Ounces ÷ 128

A note on mixing buckets: Never mix an exact, to-the-ounce batch in a container that is exactly that size. You must use a mixing bucket large enough to allow aggressive stirring without spilling over the sides, as improperly mixed resin will result in soft, sticky spots that never fully cure.