Epoxy Pour Calculator
Measure the channel, get ounces, liters, and the exact Part A / Part B split — with a warning when your pour is too deep for table-top resin.
Checks: Not independently benchmarked. Method: unit conversions; pour-depth limits are product-specific, so check your resin data sheet. · Last reviewed October 20, 2026
87.8 US fl oz mixed
2.60 L · 0.69 gal · includes 10% waste
Measure out: Part A (resin) 58.5 oz (1730 ml) + Part B (hardener) 29.3 oz (865 ml)
Mix ratio must follow your product’s data sheet. This calculator splits by volume at 1:1 or 2:1; if your product uses another ratio, or specifies by weight (not the same, because resin and hardener densities differ), follow the data sheet instead. River-table channels aren’t perfect rectangles: live edges add and remove volume, so treat the rectangle as an estimate; the waste allowance covers the rest.
The formula, shown
Volume = L × W × D, then in³ × 0.554 = US fl oz. Worked example: a 24″ × 4″ × 1.5″ channel is 144 in³ ≈ 79.8 oz; with 10% waste, mix ~88 oz. At a 2:1 ratio that’s 58.5 oz Part A + 29.3 oz Part B.
Pouring without regrets
- Seal first. A thin seal coat on the wood helps stop bubble streams from the grain; one table-top epoxy’s data sheet says to always seal wood before flood coating.
- Respect max depth. The calculator warns past 2″ — but the real limit is your product’s data sheet, and temperature and batch size change how much heat builds up.
- Mix what the math says, not what feels safe: a big batch builds heat in the bucket (one table-top data sheet caps a single mix at one gallon). Two medium batches beat one giant one.
- Level the form — epoxy is a liquid level; a 1° tilt on a 48″ table is a 0.8″ wedge.
Frequently asked questions
How much epoxy do I need for a river table?
A typical river channel 48″ long × 5″ wide × 1.5″ deep is 360 in³ ≈ 200 fl oz ≈ 1.56 gallons before waste. Real channels aren’t rectangles — live edges give and take — so treat the rectangle plus a 10% allowance as a starting estimate, not a guarantee.
What’s the difference between table-top and deep-pour epoxy?
Cure heat. Epoxy cures exothermically, and thick masses trap the heat. One table-top epoxy’s data sheet limits it to 1/8–1/4″ per coat and warns that more can overheat the cure, with a wavy surface, yellowing, and cracking. Deep-pour (casting) formulas are made to cure slower and cooler: one casting epoxy’s data sheet allows up to 3″ per layer, and less for big volumes. Limits differ by product, so use the one on your resin’s data sheet.
Is the mix ratio by volume or by weight?
Check your label — it matters. Many hobby epoxies specify by volume (1:1 or 2:1 with measuring cups), but some specify by weight, and the two are not interchangeable because resin and hardener have different densities: one table-top epoxy’s data sheet gives 1:1 by volume but 100:83 by weight. An off-ratio mix can cure soft or tacky, so measure carefully.
How much extra should I mix?
A 10% allowance is the default here — a rule of thumb for cup residue, seepage into wood grain and cracks, and topping off shrinkage, not a figure from a data sheet. Go 15% for very porous slabs or complicated molds. Running out mid-pour can leave a visible line where the second batch meets the first, so mixing slightly over is the cheap insurance.
Sources & further reading
- Volume conversions: 1 in³ = 0.554 US fl oz; 231 in³ = 1 US gal; 61.02 in³ = 1 L
- Maximum pour depth is product-specific — always confirm on your resin’s technical data sheet before a deep pour
- TotalBoat TableTop Epoxy technical data sheet (March 2022) — maximum 1/8–1/4 in per coat, with excess heat showing as a wavy surface, yellowing and cracking; mix ratio 1:1 by volume, 100:83 by weight; seal coat on wood
- Passeport Élite Casting Epoxy technical sheet — castable thickness up to 3 in (7.5 cm) per layer, less for pours over 18 L; mix ratio 2:1 by volume, 100:45 by weight
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