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Epoxy Resin Calculator – How Much Epoxy You Need

Learn how to calculate the amount of resin you need for any DIY project with a simple epoxy resin calculator.

Most epoxy calculators only provide rough estimates.
They focus on calculating volume instead of how to properly measure a resin area.

So today, I will take a different approach.
Rather than provide a simple resin volume calculator, I will talk about how to take accurate measurements for any given project size or shape.

At the end of this article, download your FREE copy of my epoxy coverage calculator.

How Much Epoxy You Need

Choose Best Epoxy Resin to Use

First, let’s talk about the best epoxy resin to use for your project.
Selecting the right epoxy resin for your project is very important to produce favorable results.

In general, there are 4 types of epoxy for common projects.

Deep Pour Epoxy

Deep pour epoxy is used for thicker pours up to 4 inches.
The 2:1 mixing ratio, thinner viscosity, and longer cure times allow for the depth of the pour to be greater than table top epoxy.
My favorite deep pour epoxy is Liquid Glass 2.0.

Table Top Epoxy

Table top epoxy works best as an epoxy top coat on tables.
Due to it’s versatility, people use it for resin art, to fill wood voids, and for resin crafts.
Essentially, table top epoxy requires a 1:1 mixing ratio and cures rather quickly.
As a result, the depth of the pour is limited to 1/8″ up to 1/4″.
My favorite table top epoxy is TotalBoat Table Top Epoxy.

Penetrating Epoxy

Penetrating epoxy is used to stabilize and seal wood surfaces.
Also, this epoxy restores rotted wood stabilizes reclaimed wood and driftwood.
The marine industry uses penetrating epoxy for wooden boat restoration.
My favorite penetrating epoxy is TotalBoat Penetrating Epoxy.

Woodworking Epoxy

Although table top epoxy works to repair wood defects, woodworking epoxy performs better.
Woodworkers use this epoxy to address defects such as knots, cracks, checks, voids, and gaps.
Furthermore, woodworking epoxy cures quickly and comes in convenient pump containers.
My favorite woodworking epoxy is TotalBoat High Performance epoxy.

How Much Epoxy Resin You Need – Volume in Cubic Inches

First, the amount of epoxy you need is based on volume.
Volume is the amount of space occupied by a three-dimensional figure as measured in cubic units.
Of course, the three-dimensional figure in this context is epoxy resin.

So, we need to find the cubic inch volume of epoxy resin to fill a space.
With this in mind, we need 3 measurements for the basic volume formula:

Volume = Length x Width x Thickness

epoxy resin calculator volume

1. Dimensions of Your Project

Before we get started, determine the shape of your project.
The basic formula to calculate volume differs depending on the shape as outlined below:

  • Rectangular
    • An example of a rectangular surface is a table top.
    • Volume = Length x Width x Thickness
  • Circular
    • An example of a circular surfaces is a round table.
    • Volume = (Radius Squared) x pi (or, 3.14159265) x Thickness
  • Irregular
    • An example of an irregular surfaces is a live edge river table.
    • Refer to real example later in this article.

2. Secure Workpiece

It’s important to layout your workpiece (if applicable) in order to get the measurements needed for the epoxy calculation.
In this picture, I secured 2 pieces of wood with clamps and a 2×4 to prevent it from moving.

secure project determine cubic inch volume

Once you secure your project, it’s time to measure the resin area.

3. Determine Depth of Your Project

Generally speaking, there are basically 2 types of epoxy resin projects:

  • With Thickness
  • Without Thickness

Epoxy projects with thickness include river table projects, epoxy river bar tops, encapsulation projects, or casting objects.
Obviously, these projects require more epoxy resin and deeper pours.

Live Edge River Table Epoxy Pour

Second, epoxy projects without depth require a thin layer of epoxy on a flat surface.
These include a table top epoxy finish, a garage floor, and epoxy resin art projects.
Often times, these projects require multiple thin pours such as an initial seal coat, followed by another thin seal coat, and multiple flood coats.

outdoor epoxy wood bar top finish
how to make resin art effects on a canvas

Projects with No Thickness

If your resin project requires deep pour epoxy or multiple thin pours of table top epoxy, I got you covered.

For epoxy projects without thickness, use 1/8″, or 0.125, as your thickness number for each epoxy coat.

Fraction to Decimal Conversion

Although you measure in fractions, you must convert fractions into decimals for the epoxy resin calculator.

fraction to decimal conversion chart

4. Measure Resin Area

First, use inches for all your measurements.
Essentially, it is easier to use square inches rather than square feet.

Irregular Surface Example

A resin river table project provides a great example.
The irregular shape of waney edge timber requires an average width calculation.

First, measure the length of the area.
This is normally the longest measurement.

Next, measure the widest part of the area.
Then, measure the thickness of the area.
Remember, this measurement will be 0.125″ if your project has no depth.

Epoxy Resin Calculator

The measurements I took for this river table to determine approximately how much resin needed are:

Length: 47″
Width: 10″
Depth: 1.5″

Due to the large surfaces of river tables, they require thicker applications.

Epoxy Resin Calculator

If your project has an irregular shape, take a measurement every 3″ to 6″ to get an average width of the pour.
You want to have at least 3 measurements.
Otherwise, you will get a rough estimate.
However, it is a good idea to take as many as possible.
The more measurements you take, the more accurate.

how much resin for river table

Add the measurements together and divide by the number of measurements you took.
Using my example, 10+9+12+11+8 = 50.
50 / 5 = 10″.

The next step is to find the volume of the resin area in cubic inches.
Volume = 47 x 10 x 1.5.
Volume = 705 cubic inches.

Rectangular Surface Example

To calculate the amount of resin needed for a table top epoxy finish,

Table Top Epoxy Calculator

Round Table Example

A round surface requires you to find the radius of a circle.
Don’t worry, finding this doesn’t require a lot of math and it’s not a tricky thing.

First, find the diameter.
Then, divide the diameter by 2.

Epoxy Calculator for Round Table

5. Conversion Formula

So, you have the volume in cubic inches from the epoxy resin calculator.
Next, determine which conversion formula below works best for you.

Gallons or Quarts

The complete formula to determine the amount of epoxy resin in gallons and quarts are:

Gallons = (Length * Width * Thickness) * .004329
Quarts = (Length * Width * Thickness) * .017316

US Fluid Ounces

To convert cubic inch volume to US fluid ounces, divide by 1.805.
705 / 1.805 = 390.581717 US fluid ounces

Finally, use the formulas below to convert to US fluid ounces to gallons or quarts:

  • Gallons = US fluid ounces / 128
  • Quarts = US fluid ounces / 32

Add 10% – Better to Have Too Much Material

Add 10% to your final epoxy resin calculator number to make sure you have enough epoxy resin.

Ultimately, it is better to have too much product than not enough.
The extra 10% takes into account the following:

  • Losses from mixing
  • Epoxy needed to cover edges
  • Porous surfaces

Plus, you can use the additional epoxy next project.
For example, you can use a silicone mold to make resin crafts.

resin silicone mold

Epoxy Resin Calculator Tip

Ultimately, the final epoxy resin calculator number represents the total amount of epoxy resin you need regardless of the mix ratio.

Epoxy resin comes in 2 parts – Resin and Hardener
Part A and Part B (resin and hardener) are mixed together causing a chemical reaction.
Then, the liquid cures into a solid during the curing process.
Most epoxy for DIY projects require a 1:1 mixing ratio while others require a 2:1 mixing ratio.

deep pour epoxy 2:1 mixing ratio


In conclusion, I hope this epoxy resin calculator helps you create an awesome epoxy project.

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