Epoxy Resin Calculator
Calculate your pour volume, resin and hardener mix, and estimated material cost.
Pour preview
Live geometryPreview shows relative proportions; depth is exaggerated for visibility.
How volume is calculated
Rectangle: length × width × depth. Round mold: π × radius² × depth. One cubic centimeter equals one milliliter. Extra allowance is added afterward.
Mix with the right measurement
Use a graduated container for a volume ratio or a scale for a weight ratio. When converting volume to weight, use the mixed epoxy density supplied for your product.
Plan the pour, not the cure
Check your product's maximum pour depth, working time, and handling instructions. This tool estimates an empty mold; subtract the volume of embedded objects separately.
Already know your batch size?
Use the Resin Mixing Ratio Calculator to split a batch in milliliters or grams without entering mold dimensions.
How to use the epoxy resin calculator
Estimate the mixed epoxy needed for a rectangular or round mold, split it into resin and hardener, and calculate a material cost. Start with the inside dimensions of your empty mold.
- Choose your shape and units. For a rectangle, enter length and width. For a round mold, enter the diameter.
- Enter the pour depth. Use the intended resin thickness rather than the full mold height if you are filling only part of it.
- Choose an extra allowance. The starting value is 10%. Adjust it for material left in the mixing container and minor spills.
- Enter the manufacturer's mixing ratio. Select whether it is measured by volume or weight. The default 2:1 is an example, not a recommendation for every epoxy.
- For weight estimates, verify mixed density. The example 1.1 g/mL must be replaced with a value appropriate to your epoxy.
- Enter a price per liter of mixed epoxy. To work it out from a kit, divide its price by the total mixed volume in liters.
Worked example: a small rectangular mold
A mold measuring 20 × 12 × 1 cm holds 240 mL. Adding 10% gives 264 mL. With a manufacturer-specified 2:1 ratio by volume, that is 176 mL of resin and 88 mL of hardener. At $35 per liter, the estimated epoxy cost is $9.24.
Planning a deep pour
The volume formula stays the same for a deeper project, but a calculator cannot determine a safe pour depth. Use the resin manufacturer's instructions for maximum depth, batch size, and working conditions. If your product requires multiple layers, calculate each layer's volume separately.
Common questions
Are grams and milliliters the same for epoxy?
No. Milliliters measure volume; grams measure mass. Converting between them requires density. A mixing ratio by weight must not be used as a ratio by volume.
Does the estimate include wood or embedded objects?
No. The estimate assumes an empty mold. Objects and wood displace resin, so the actual resin requirement may be lower. For a river table, estimate the resin channel rather than the entire tabletop.
What is a round mold?
A circular base with straight sides, calculated as a cylinder using diameter and pour depth. Domed, tapered, and irregular molds need a different volume estimate.
Why might the amount I use differ?
Rounded measurements, uneven surfaces, absorption, embedded objects, and residue affect the actual amount. The result is a planning estimate, and the preview exaggerates depth for visibility.