Epoxy & Resin Calculator
Calculate exactly how much resin you need for your project. Choose a shape, enter the dimensions, and avoid wasting expensive epoxy.
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How to Calculate Epoxy Resin Accurately
Whether you're pouring a massive river table, crafting a circular table, or creating small resin art, getting the precise amount of epoxy is critical. Running out of resin mid-pour ruins the project, while mixing too much wastes expensive materials. Our epoxy resin calculator uses standard geometric formulas and typical coverage rates to eliminate the guesswork.
The Fundamental Volume Formula
For rectangular molds, the math is straightforward: you calculate the volume in cubic inches (or centimeters) and convert it to gallons or liters. For round projects, you calculate the area using the diameter, then multiply by the depth. The basic formulas are:
Circles: π × (Diameter ÷ 2)² × Depth = Total Volume
However, pure math doesn't account for real-world application. Some epoxy always clings to the mixing bucket, seeps into porous surfaces (like wood or concrete), or is lost due to surface tension. That’s why professionals always factor in a 5% to 10% safety margin (which our calculator handles for you automatically).
Understanding Mix Ratios (Part A & Part B)
Total volume is only half the battle. Epoxy systems consist of two components: Part A (Resin) and Part B (Hardener). Getting the ratio wrong will result in a sticky, uncured mess. The most common ratios are:
- 1:1 Ratio (By Volume): Most standard tabletop and coating epoxies use this. It’s equal parts resin and hardener.
- 2:1 or 3:1 Ratio: Often used for deep pour and casting resins. These take longer to cure but allow for thicker single pours (up to 2-4 inches) without dangerously overheating.
Always verify the mix ratio on your specific brand's label. Our tool breaks down the exact amounts of Part A and Part B you need based on your chosen ratio.
Frequently Asked Questions
How much epoxy do I need for a river table?
A standard river table isn't purely resin—the live-edge wood slabs take up a massive amount of volume. On average, a river table consists of roughly 40% wood and 60% resin space. If you select the "River Table" shape in our calculator, it automatically applies a wood displacement formula so you don't over-buy material.
Can I pour it all at once?
It depends entirely on the type of epoxy. Table top epoxy is designed for thin coats (usually 1/8" to 1/4") and cures fast. If you pour it too thick, it will flash-cure, crack, and turn yellow. For thick applications, you must use a deep pour (casting) resin, which cures slowly over 48–72 hours, allowing heat to escape.
Why do I need to calculate by volume and not weight?
While some specific industrial epoxies are mixed by weight, the vast majority of consumer resins (like ArtResin, Liquid Glass, or SuperClear) are formulated to be measured strictly by volume. Resin (Part A) is generally denser and heavier than hardener (Part B). If you weigh a 1:1 volume kit, you will actually throw the chemical reaction off balance.