Epoxy calculator
How much resin a table, river, coaster or tumbler actually takes — split into resin and hardener, in millilitres and grams at once, with your resin's own pour depth ceiling checked before you mix anything.
INPUTS
A dining or coffee table getting its glossy coat. One flood at the full ceiling; a second coat doubles the resin, not the depth of the first.
The glossy coating one. Built to be poured thin over a surface and self-level into a hard, clear film — bar tops, counters, artwork, tumblers. It is fast, and the speed is the point: a coat is dust-free in a few hours instead of a few days. Maximum 3.2 mm in one pour.
Identical pieces from one mix.
Counters, bar tops, boards, trays, panels. Measure the inside of the form, not the outside.
mm
mm
mm
An eighth of an inch per flood coat. That is not a suggestion about finish quality — a table top system reaches its peak reaction temperature in twenty minutes or so, and depth is what decides whether that heat can escape into the room or stays trapped in the middle of the pour. Build up thickness with several coats, letting each one firm up first.
Pigment and wastage
AdditiveDose
0.0% filler by weight
%
What stays in the cup, on the stick and off the edges. You cannot go back for more mid-pour, so mix long.
3238 ml is a lot of fast resin to have in one cup. Depth is not the only thing that traps heat — a deep, narrow container of table top / coating epoxy can start to smoke while you are still stirring, and its 20-minute working time is measured from a small mix, not this one. Split it into 4 batches of about 946 ml, mix each in a wide vessel and pour it out before starting the next.
Working time is 20–40 minutes from the moment the two parts meet, and it runs shorter in a warm room and in a bigger mass. Have the mold levelled, the torch to hand and everything taped before you open a bottle.
Uncured epoxy is a skin sensitiser and the sensitivity is cumulative. Nothing may happen for a year of bare-handed work and then a reaction develops that does not go away — at which point the craft is over for you. Nitrile gloves every time, including the pours you think are too small to bother with. Vinyl and latex are not adequate; the resin goes through them.
RESULTS
Mix this much
3238 ml
109.5 fl oz 3.24 L 0.86 US gal 3400 g
Measure out
| Part | By volume | By weight |
|---|---|---|
| Resin | 1619.1 ml | 1781.0 g |
| Hardener | 1619.1 ml | 1619.1 g |
1:1 by volume is 1.10:1 by weight, because resin is the
denser of the two. Both columns are the same mix — do not read one number off the bottle and measure with the
other. The mix ratio calculator works it the other way round, from
whatever you have left in a bottle.
Pours needed
1
The void itself
2944 ml
Depth ceiling, this resin
3.2 mm
You are pouring
3.2 mm
Volume is worked out from the void you are filling, then the wastage is added — a mixing cup keeps a film you
cannot get out, and running short halfway through a pour leaves a line you cannot sand away. The resin and
hardener split uses this system's own ratio and nothing else, which is why changing the resin at the top
changes every figure here. Ceiling: 3.2 mm (1/8 in) per pour.
Print the pour-depth card
Maximum pour depth and cure windows by resin type — the number that cracks a casting. Free.
How this is worked out
Everything starts from the void you are filling. One square centimetre poured one millimetre deep is 0.1 ml, exactly, so the volume is the shape's area times the depth and every "coverage per gallon" figure is that sum wearing different units. A river channel is the one shape that is not a straightforward multiplication: it is the form minus what the two slabs displace, up to their own thickness, because above that the resin simply runs over the top of them. Then the wastage goes on — 10% by default, higher than the other crafts on this site for a reason specific to resin: a mixing cup keeps a film you cannot get out, and there is no going back for more once 20 minutes of pot life have started. The split into resin and hardener uses the chosen system's own ratio, and the weights come from their own densities, which differ — so the tool reports both conventions rather than picking one. Finally the depth is checked against that system's own ceiling and turned into a number of lifts, because "you need 18.12 litres" is arithmetically true and practically useless if it arrives without "in one pour".
void = area × depth × 0.1 1 cm² × 1 mm = 0.1 ml, exactly
river = form − slabs × min(slab thickness, depth)
mixed = void × pieces × (1 + wastage) wastage 10% by default
resin = mixed × ratio ÷ (ratio + 1) the SYSTEM’S OWN ratio
weight = each part × its own density resin 1.1 g/ml, hardener 1 g/ml
lifts = ceil(depth ÷ ceiling) Table top 3.2 mm · Deep pour 51 mm
Questions makers ask
How much epoxy do I need?
It follows from the area and the depth, and nothing else — one square centimetre poured one millimetre deep is 0.1 ml, always. So a table top flood coat, 4 ft at 1/8 in takes about 3.24 litres, and coasters, set of 8 take 691 ml. Both figures already include 10% for what stays in the cup — which is not padding, because you cannot go back and mix more once a pour has started.
How do I calculate epoxy for a river table?
Not by multiplying three numbers together, which is why most answers come out enormously too high. A river table is a form containing two slabs, so the resin fills the gap between them and covers the wood only if the pour is deeper than the slabs are thick — the volume is the form minus what the wood displaces. A river table, 6 ft with a 200 mm average river comes to about 18.12 litres, or 4.79 US gallons. Measure the gap at several points along the live edge and average it; a live edge is wavy and one measurement will be wrong.
How much epoxy per square foot?
At 1/8 in, one US gallon covers 12.8 square feet. You will see 12 square feet printed on a great many tins, and the gallon has not shrunk — the printed figure has about 6% waste allowance already folded into it, for what stays in the cup, runs off the edges and gets skimmed away with the bubbles. Coverage halves every time you double the depth, so a figure quoted without one is meaningless.
How deep can I pour epoxy in one go?
That depends entirely on which epoxy, and the difference is about tenfold. Table top / coating epoxy tops out at 1/8 in (3.2 mm) per flood coat; deep pour / casting epoxy goes to 2 in, and some systems to 4 in in a cool room. This is the one figure on this site where being over is a hazard rather than a disappointment: epoxy cures by a reaction that gives off heat, the heat speeds the reaction up, and a deep mass of the wrong resin gets hot enough to crack itself, smoke and scorch what it is standing on. A 10 mm coaster is 4 separate coats in a table top system and one pour in a deep pour one.
Does the epoxy resin calculator work in grams?
Yes, and it shows both at once, because they are not interchangeable. Resin runs about 1.1 g/ml and hardener about 1, so 2:1 by volume is 2.20:1 by weight — take the by-volume number to a scale and you put in roughly 7% too much hardener. The excess has nothing to react with, so it stays in the piece and keeps it tacky. That single confusion is the commonest cause of a first batch that never hardens.
What is the epoxy mix ratio?
It is a fixed property of the product, not a dial. Table top / coating epoxy is usually 1:1 by volume and deep pour / casting epoxy 2:1, and both react in fixed proportion — adding more hardener does not speed the cure and adding more resin does not make it harder. Both give the same result, which is a surface that stays sticky. <a href="/resin/mix-ratio-calculator">The mix ratio calculator</a> runs it the other way round, from whatever is left in the bottle you have.
How much resin does a tumbler take?
Far less than people expect, because a tumbler is coated rather than filled — the resin is a skin over the outside, not the cup's capacity. A tumbler, 20 oz coated 0.5 mm thick over 200 mm of its height comes to about 31 ml. The calculator treats it as a straight cylinder, which runs slightly generous on a tapered cup — the right direction to be wrong in.
How long does epoxy take to cure?
Table top / coating epoxy has 20–40 minutes of working time, can be handled after about 24 hours and reaches full hardness at 72 hours. Deep pour / casting epoxy trades all of that for depth: 3–5 hours of working time, 48 hours to demold and 7 days to full cure. The slow reaction is exactly what lets it shed its own heat at 2 in.
How much pigment can I add?
About 6% by weight for mica powder and liquid pigments, and less than most people assume — half a per cent is already a solid color. Nothing you stir in takes part in the reaction, so past that ceiling there is not enough resin bridging between the particles and the pour stays faintly soft rather than failing outright. Glow powder is the exception at 10–20%, because it is a coarse inert crystal rather than a fine platelet — and it has to be, or it barely glows.
Is UV resin the same thing?
No. UV resin is one part, has no hardener and no mix ratio at all, and sets under a 3 mm lamp rather than by reacting with anything. Its depth limit is optical rather than thermal: the resin absorbs the light that cures it, so a thick pour skins on top and stays liquid underneath permanently. None of the figures above apply to it. <a href="/uv-resin">The UV resin guide</a> covers it on its own terms.
Read before your next batch
- How to make resin art Buy the right resin for the depth you are pouring, weigh both parts rather than eyeballing them, and leave it alone once it is poured. Almost every first-batch failure is one of those three.
- UV resin One part, no hardener, no measuring, and set in about a minute. It is a genuinely different product from two-part epoxy, and its limits are not the ones you would guess.
- Resin vs epoxy: which type to buy Four products share the word, and the one thing that separates them is how deep you can pour them. Pick by that, and everything else follows.
- Deep pour vs table top epoxy Two clear liquids that look identical in the bottle, with maximum pour depths about ten times apart. Going past the wrong one is a heat problem, not a patience problem.