Volumes split by the ratio on your product’s label, in the basis it uses
Epoxy fails more often from arithmetic than from chemistry: the right total poured in the wrong proportion stays sticky forever. This calculator works out the pour’s total volume from its shape and depth (or takes a volume you already know), adds your waste allowance for the cup and the drips, and splits the mix into resin and hardener by your product’s ratio in the basis the label states it, by volume or by weight, converting between them with densities when the basis is weight. It also counts the pours: a product rated for a shallower layer than your depth needs layers, and the results say how many and how deep each is, because exotherm, the heat a thick pour generates, is the failure mode nobody budgets for.
Disclaimer: This calculator gives estimates for general information only. It is not financial, medical or other professional advice. Follow your product’s label and safety data sheet for ratios, pour limits, ventilation and protective equipment; the label governs over any calculator.
What this calculator does
Resin work prices its mistakes in ruined tabletops, so the estimate carries the three numbers the label leaves you to derive: how much mixed resin the shape actually holds, how that total divides between the bottles, and how many separate pours the depth demands. The ratio split is where this page earns its keep: a 2:1 by volume is not a 2:1 by weight unless the two liquids share a density, and they never do, so the basis selector and the density fields exist to make the conversion the label expects and most calculators silently skip. The layers count is the other quiet rescue: deep-pour and tabletop products differ mainly in how much heat they can shed, and pouring a tabletop resin at deep-pour depth cooks it from inside.
How to use it
- Depth is the pour’s, not the mould’s. A river table’s resin channel takes the resin’s depth; a coating takes an eighth of an inch over the whole top. For moulds with objects inside (wood slabs, inclusions), subtract their volume or use the known-volume mode with your best displacement estimate.
- Read the ratio off your label, and its basis with it. Manufacturers print both; the pump kits that dispense 1:1 by volume are a convenience, not a chemistry fact, and weighing a volume-ratio product without the density conversion is the classic route to a tacky cure.
- Waste is real, and small pours waste proportionally more. What coats the cup, the stir stick and the mixing bucket never reaches the mould; 5 percent flatters a big pour and 15 is honest for small ones.
- The maximum pour depth is a product property. It is printed on the label and differs fourfold between product families; the layers result divides your depth by it and states each layer’s depth, and pouring thicker “to save time” is how exotherm cracks, yellows and foams a pour.
The method
- Volume: rectangle = L × W × depth; circle = π × (diameter/2)² × depth; conversions at 16.387064 mL per cu in and 29.5735 mL per fl oz. Mix total = volume × (1 + waste%).
- Split by volume: resin = total × resin part / (resin + hardener parts); hardener likewise.
- Split by weight: the parts’ weights follow the ratio, so the volumes follow weight/density: with t = total mL / (resin part/d resin + hardener part/d hardener), resin volume = t × resin part/d resin, and each part’s weight is its volume × density.
- Layers = depth / maximum per-pour depth, rounded up; each layer is the depth divided equally. Kits = mix total / kit size, rounded up.
Worked examples
The flood coat. A 48 by 24 in top at 1/8 in is 144 cu in: 2,359.74 mL (79.79 fl oz). A 1:1 by volume splits it into 1,179.87 mL of each, and at a 1/4 in tabletop-product limit the coat is a single pour, as flood coats are meant to be. The same top costed as a 1/16 in seal coat first would take half of this again across the two coats, which is why manufacturers quote coverage at a stated thickness, and why thickness is an input here, never an assumption.
The river pour. A 36 by 18 in channel at the full 2 in depth of a deep-pour product is 1,296 cu in: 21,237.63 mL (718.13 fl oz), splitting at 2:1 into 14,158.42 mL of resin and 7,079.21 mL of hardener. At a 2 in per-pour limit it is one pour; at a 1/2 in tabletop limit the same channel is four pours, the practical difference between a weekend product and a workbench product.
Reading your results
Read the split in the unit your measuring uses: jugs and pumps work in volume, scales in grams, and the results give both whenever densities are provided. Read the kit count as a floor, not a target: resin has no shelf mercy once mixed, but an unopened spare kit returns, while a pour short by a cup does not forgive. And read the layer depths as a schedule: each layer needs its cure window from the label (pour too soon and the layers blend chemically hot; too late and they bond mechanically to a sanded surface instead), so the count translates directly into days on the calendar.
Limitations
- Densities vary by product and temperature. The weight conversion is only as good as the densities entered; the label or data sheet prints them, and typical ranges are given beside the fields for the many labels that do not.
- Volume displacement is the estimator’s. Wood, stones and inclusions displace resin irregularly, and porous wood also drinks a seal coat; the known-volume mode exists for your measured displacement, which beats any shape formula on real projects.
- Exotherm depends on mass and shape, not depth alone. A wide shallow pour sheds heat a narrow deep one cannot; the layers result enforces the label’s depth limit, which is the manufacturer’s own proxy, and unusually large masses deserve a test pour regardless.
- Cure behaviour is the label’s subject. Working time, cure windows between layers, temperature ranges and food-contact status all live on the product’s documents; this page counts material and takes no position on any of them.
Frequently asked questions
What happens if the ratio is off?
The excess component has nothing to react with, so the pour stays soft or tacky in proportion to the error, and there is no later fix that reaches inside a cured mass: small surface tack sometimes yields to a correctly mixed flood coat over it, and anything deeper is a removal. That asymmetry, fatal downside against trivial effort, is why the split deserves its own arithmetic with the basis checked, rather than a confident pour from the bottle marks.
Can I mix by weight a product rated by volume?
Yes, with the density conversion this calculator performs: weigh each part at its volume × its density, and the parts land in the volume ratio the chemistry wants. What cannot be done is weighing the ratio directly (a 2:1 by volume weighed out at 2:1 by weight under-doses the denser component systematically), which is among the most common causes of the sticky pour described above, because scales feel more accurate than the conversion they skipped.
Why did my pour get hot, smoke or crack?
Exotherm: the curing reaction releases heat, thick masses insulate themselves, the centre runs hotter, curing faster, releasing heat faster still. The defences are all in this page’s inputs: respect the product’s per-pour depth, split the depth into the layers the results count, and treat total mass with the same suspicion as depth. A pour that has yellowed or cracked from heat is a removal too, which is why the layer count prints before any kit count.
How much extra should I mix?
The waste field’s honest answer: enough to coat every surface the resin touches on its way, which scales with the number of transfers and the pour’s awkwardness more than its size. Professionals mix a measured surplus and keep the second cup’s worth unmixed in reserve for the leak and the thin corner; the calculator’s percentage simply makes the surplus a decision instead of a hope.
Related calculators
Method: volume from shape and depth (or a known volume), split by the label’s ratio in its stated basis with density conversion for weight, layers from the product’s per-pour depth limit, and kits at the selected size. Last reviewed: 15 October 2026.