Epoxy resin calculator
How much epoxy do you need? Measure the pour, pick the mix ratio and get liters, fluid ounces and gallons — split into parts A and B, with layer guidance and a cost estimate. Pricing the slabs too? The board foot calculator handles the wood side; flattening with a router sled? Check the router speed calculator.
0 L
total mixed resin including waste
| Pour volume | 0 L |
| Part A — resin | 0 L |
| Part B — hardener | 0 L |
| Pours needed | – |
| Estimated resin cost | €0.00 |
How the epoxy math works
Pour volume is length × width × depth in inches, converted at 0.01639 L per in³. The seal-coat mode works from square feet instead:area × 144 × coat thickness — 1 US gallon covers about 12.8 ft² at the standard 1/16 in flood coat. The waste percentage pads the total for what stays in the mixing cups, the mix ratio splits that total into parts A and B by volume, and the cost line multiplies by your price per liter.
Layer guidance follows common deep-pour practice: up to 2 in per pour for small castings, but only about 0.5 in per layer for large river-table and slab pours, where the exotherm of a big mass can otherwise overheat, crack or yellow the resin.
Worked example: epoxy for a 60 in river table
A walnut river table, 60 in long, river channel averaging 8 in wide, slabs 1.5 in thick. Channel volume is 60 × 8 × 1.5 = 720 in³, which is 11.8 L. With the default 5% waste allowance you mix 12.4 L — about 3.3 US gallons. At a 2:1 ratio that is 8.3 L of resin and 4.1 L of hardener, measured by volume and stirred until the streaks disappear.
A 1.5 in river is not one pour. Deep-pour resin tolerates 2 in per layer in a small casting, but a river channel holds a far larger mass and the exotherm stacks up, so the practical limit is about 0.5 in per layer — three layers here. Pour, wait for the layer to gel and cool, pour the next. In a cold shop that can mean a day between layers. Once cured, the slab is flattened with a router sled — the router speed calculator keeps the surfacing bit inside its RPM limit.
Seal first. A brushed 1/16 in coat over the channel faces soaks into the grain and stops air bleeding out of the wood into the clear pour — that bleeding is where the bubbles come from. The 60 × 8 in channel needs roughly half a liter per coat.
At 40 per liter the resin bill lands near 496, so measure twice: the board foot calculator prices the slabs, and the cut list optimizer plans the melamine mold and any sheet goods for the base.
Frequently asked questions
How much epoxy do I need for a river table?
Measure the river channel: length × average width × pour depth in inches, then multiply by 0.01639 to get liters. A 60 × 8 × 1.5 in river is 720 in³ — about 11.8 L, or 12.4 L with a 5% waste allowance. Live edges make the width vary, so average a few measurements. The river table mode here does that math and splits the total into parts A and B at your mix ratio.
Why can’t I pour the full depth in one go?
The cure reaction is exothermic — it generates heat, and heat speeds the reaction further. In a thick, large pour the heat has nowhere to go and can crack, yellow or even foam the resin. Deep-pour resins are rated for up to 2 in per layer in small castings, but for large river-table and slab pours the practical limit is about 0.5 in per layer. The pours-needed line counts your layers at those limits.
Is the mix ratio by volume or by weight?
This calculator splits by volume, because most tabletop and deep-pour epoxies spec their 1:1, 2:1 or 4:1 ratio by volume. Only measure by weight if the datasheet gives a weight ratio — the two are different numbers, since resin and hardener have different densities, and swapping one for the other is a classic way to get a pour that never cures.
Why add a waste allowance?
Some resin always stays in the mixing cups, on the stir sticks and in the corners of the mold, and live-edge voids swallow more than the tape measure suggests. 5% covers a clean, well-dammed pour; raise it to 10% for rough live edges or a first river table. Running out mid-pour is far worse than a cup left over — a partly filled channel leaves a visible seam between pours.
What is a seal coat and why bother?
Wood is full of air. A thin brushed-on coat — about 1/16 in — soaks into the grain and locks that air in before the flood or deep pour goes on. Skip it and the wood breathes bubbles into your clear pour for hours. The flood/seal mode sizes this coat from your surface area; one coat is usually enough, two for very porous or punky wood.