Resin Calculator

Coatings, castings, or river tables: enter your dimensions and get total resin, Part A/B splits, layer count, and kit size in one pass.

Seal coat: 0.3–0.5 mm, flood coat: 1–2 mm, self-level floor: 2–3 mm.

Match what your resin datasheet specifies.

Covers mixing cup losses, edge drips, and minor absorption.

How to Calculate Resin for Any Project

Resin quantity is always volume first. You calculate the space you need to fill, apply your waste factor, then split that total volume into Part A and Part B using your product's mix ratio. Whether the ratio is by volume (2:1, 1:1) or by weight (100:45), the calculator handles the split and converts between the two so you have both figures available when measuring out your components.

The most common mistake is confusing a volume ratio with a weight ratio. A 2:1 volume ratio means 2 parts of Part A by volume to 1 part of Part B by volume. That is not the same as 2:1 by weight, because Part A and Part B often have different densities. Always check your product datasheet to confirm whether the ratio listed is by volume or by weight before you start measuring.

Project Types and What to Measure

For coatings and floor applications, you need the surface area and the target film thickness. A flood coat on a tabletop at 1.5 mm over a 2.4 x 1.2 m surface takes roughly 4.3 litres before waste. For castings, you measure the internal mold dimensions: length, width, and height. For river tables, you measure the river channel length, the average channel width (live-edge channels taper, so take a few measurements and average them), and the pour depth.

Layer Planning and Why It Matters

Epoxy resin cures exothermically, meaning it generates heat as it sets. In thin coating applications this isn't a problem, but in deep pours the heat can build up faster than it dissipates. If you exceed your product's maximum safe pour depth in a single layer, the resin can crack, yellow, or cure with trapped bubbles. The calculator divides your total depth by the max pour depth and gives you the number of layers required, along with the volume per layer. Each layer typically needs to be partially cured before the next is poured.

Resin Types and Typical Applications

Resin Type Typical Film / Pour Depth Common Use
Table / art epoxy 1–6 mm per coat Tabletops, artwork, flood coats
Self-levelling floor epoxy 2–3 mm per coat Garage floors, commercial surfaces
Deep-pour casting epoxy 25–50 mm per layer River tables, encapsulations, blocks
UV resin 1–5 mm (cure depth limited) Jewellery, small crafts, thin fills
Polyester / polyurethane casting Varies widely by product Moulds, prototypes, decorative casting

Rough Resin Costs by Type

Resin pricing varies significantly by brand, volume purchased, and product grade. These are approximate US retail prices as of 2025 for planning purposes.

Resin Type Approx. Cost per Gallon Notes
Table / art epoxy $50 – $120 Price drops significantly for 5+ gallon kits
Deep-pour casting epoxy $60 – $140 Slower cure = safer for thick pours
Self-levelling floor epoxy $40 – $90 Often sold as combined A+B kit by coverage area
UV resin $80 – $200+ Small volumes; mainly for crafts and repairs

Buying in bulk (5 gal kits vs 1 gal kits) typically reduces unit cost by 20 to 40%. For river table projects, factor pigment at $10 to $30 per pour depending on colour and brand.

Frequently Asked Questions

A volume ratio means you measure Parts A and B by how much space they take up, using graduated cups or measuring containers. A weight ratio means you measure by mass on a scale. The two are not interchangeable because Part A and Part B typically have different densities, so the same volume of each will weigh different amounts. Always check which method your product specifies and stick to it.
Epoxy cures exothermically, generating heat as the chemical reaction progresses. In a thin coating the heat escapes quickly, but in a deep pour the heat builds up in the centre faster than it can dissipate. Exceeding the safe pour depth causes the resin to overheat, which can result in cracking, yellowing, excessive shrinkage, or a batch that never fully cures. Your product datasheet will specify the maximum safe depth per layer.
Most epoxy manufacturers recommend keeping pigment at 1 to 5% of the total mixed resin weight. Going above that can interfere with the curing chemistry and leave you with a soft or tacky surface. Mica powder pigments are generally safer at slightly higher percentages than alcohol inks or liquid pigments, but the specific limit depends on the product.
Resin is sold in fixed kit sizes (1 gal, 2 gal, 5 gal, etc.) and you can't partially return an opened kit. The kit suggestion finds the combination of standard kit sizes that covers your total volume with the least leftover, so you're not buying more than you need. For large projects, one larger kit almost always works out cheaper per litre than multiple small ones.

Resin Project Planning Checklist

Before you mix, confirm surface prep, ambient temperature, humidity, and pot life against your working time so nothing goes wrong mid-pour.

Download Checklist (PDF)

Planning use only. See Methodology and Data Sources. View all project checklists →

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Disclaimer

Results are approximate planning estimates only. Actual coverage may vary based on surface porosity, preparation method, ambient temperature, application technique, and product-specific characteristics.

Multi-coat systems and porous substrates may increase total material usage. Always follow your product's datasheet for cure schedule, pot life, and safety requirements.

See our Methodology and Data Sources for details.