Getting a precise measurement is simple:

1. Select the Shape that best matches your mold (e.g., a coaster is a cylinder).
2. Measure the INSIDE of your mold carefully using a ruler or measuring tape. For height, this is the depth you plan to pour.
3. Select your units (cm or inches) and enter the dimensions into the corresponding fields.
4. Select the Mix Ratio specified by your resin manufacturer (usually 1:1 for art resins).
5. Click “Calculate” and get the exact amounts you need to mix for a perfect project!

Always check your specific epoxy product label for the correct mixing ratio. Most epoxy resins use a 2:1 ratio (2 parts resin to 1 part hardener), but some use 1:1 or 3:1 ratios.

• The Water Trick (for Irregular Shapes): If your mold has a weird shape (like a crystal or an animal), fill it with water to your desired pour height. Then, pour that water into a measuring cup. The volume of the water is the exact total volume of resin you need!
• Always Mix a Little Extra: We always recommend adding 5-10% to your final calculated volume. This covers the small amount of resin that will inevitably stick to your mixing cup and stir stick.
• Inside Dimensions Only: Remember to measure the internal dimensions of your mold, not the outside.

This calculator is specifically designed for two-part epoxy resins, where a precise mix ratio of Part A (resin) and Part B (hardener) is crucial for a successful cure. UV resin is a single-part system that doesn’t require mixing, and it’s typically used for very thin layers or coatings directly from the bottle, making this type of volume calculation less necessary.

This is critically important. Volume and weight are not the same because resin and hardener have different densities (one is typically heavier than the other for the same volume). Therefore, a 1:1 ratio by volume will NOT be a 1:1 ratio by weight.

The golden rule is: Always follow the instructions provided by your resin’s manufacturer. If their instructions say, “Mix 1:1 by volume,” use graduated measuring cups as our calculator assumes. If they say, “Mix 100:42 by weight,” you absolutely must use a digital scale. Ignoring this is the #1 cause of sticky, uncured resin.

It’s best to consider any epoxy coverage calculator a good starting point, but there are other factors and variables that might impact how much epoxy you will need. Porous surfaces that require a seal coat will increase the amount of resin needed. How are you handling the edges of the surface? You will need more if you are allowing epoxy to run over the edges, compared to building a dam or wall. And, you’ll probably lose a little to mixing or overflow. For most epoxy applications, 5-10% extra should be added to account for the inevitable wasted epoxy that stays on the stir stick, or stays in the bottom corners of the mixing cup, or accidental drips.

Most common table top and bar top epoxies provide approximately 12 sq feet per mixed gallon coverage at 1/8″ thickness. When in doubt, buy more. We aren’t telling you that to trick you into purchasing more resin than you need! It’s a lot better to have a little extra on-hand than to run out in the middle of a project and have to start all over.

When it comes to coating a rectangular surface, the basic formula for table top epoxy resin coverage is quite simple:

First, measure the piece. You’ll need to know length and width in inches. You’ll also need to know how thick you’d like the epoxy finish to be. Multiply these 3 measurements together to calculate the volume for the top of the table (or bar, or countertop) in cubic inches. To convert cubic inch volume to US fluid ounces, divide by 1.805. To convert ounces to gallons, divide by 128.

Working with a round table? Easy. For a round surface, you will need to measure the diameter. Divide the diameter by 2 to calculate the radius. To calculate volume in cubic inches: (radius squared) X pi (or, 3.14159265) x (desired epoxy coating thickness). Divide by 1.805 to convert cubic inch volume to US fluid ounces. To convert ounces to gallons, divide by 128.

Remember, these formulas don’t address epoxy needed to cover the edges or any losses from mixing or pouring.

A seal coat should only be needed for wood or otherwise porous materials. This prevents air bubbles from coming out of the substrate while the flood coat is applied later. To apply a seal coat, brush on, or apply a thin layer of epoxy to the surface. A few minutes after applying the seal coat, observe the sealed material. Apply more epoxy to areas that have absorbed the initial seal coat. Allow the seal coat to cure prior to applying the flood coats. A table top seal coat is generally 1/8in