Epoxy Resin Calculator
Enter the size of the area you want to pour and how deep. The calculator shows the total amount of epoxy to mix and how much resin and hardener to measure, with an allowance for waste.
How to use this Epoxy Resin Calculator
- Choose a rectangle or a circle and the unit you measured in.
- Enter the length and the width, or the diameter of a round pour.
- Enter the depth of the pour. Check the maximum depth per layer for your product.
- Keep or change the waste allowance.
- Enter the mix ratio from the label, then press Calculate.
How to calculate how much epoxy you need
The volume of the pour in cubic inches is converted to fluid ounces, then split by the mix ratio.
- Volume = length x width x depth (or pi x radius squared x depth)
- Fluid ounces = cubic inches / 1.805
- Total to mix = fluid ounces x (1 + waste)
- Resin = total x resin parts / (resin parts + hardener parts)
Worked example
You want to pour a rectangle 24 inches by 12 inches to a depth of 1/8 inch. The volume is 24 x 12 x 0.125 = 36 cubic inches, which is 19.95 fl oz. With 10% waste the total to mix is 21.94 fl oz, or 649 mL. With a 1:1 ratio you measure 10.97 fl oz of resin and 10.97 fl oz of hardener.
Mixing in small batches is safer than making one big batch. Deep pours make heat and can crack or yellow, so many products need layers of a limited depth. Always measure the two parts exactly, since a wrong ratio can leave the epoxy sticky. Mix for the full time on the label, scrape the sides and bottom of the cup, and pour into a second cup before you use it. Test a small batch first and work in a warm room, because cold slows the cure. Keep a few spare cups, sticks and gloves ready before you start, and cover the work to keep out dust while it cures.
Assumptions & limits
- The mix ratio is by volume. Some products use ratios by weight, so check the label.
- The calculator assumes a flat, level pour with no dams, molds with texture or inclusions that take up volume.
- The waste allowance is a guess you can change.
- Maximum depth, cure time and temperature limits depend on the product. Follow the maker.
- Always wear gloves and work in a ventilated area.
Frequently asked questions
How do I calculate how much epoxy I need?
Multiply length by width by depth in inches and divide by 1.805 to get fluid ounces. Then add waste.
How much resin and hardener do I mix?
Split the total by the ratio on the label. A 1:1 ratio is half and half.
How deep can I pour epoxy?
It depends on the product. Check the label for the maximum depth per layer.
Is the mix ratio by volume or weight?
Check the label. Many table-top products are by volume.
Why add waste?
Resin sticks to cups and tools, and molds and surfaces are never perfect.
Can I use milliliters?
Yes. The calculator shows both fluid ounces and milliliters.
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Last updated: November 2026