Casting & Resin guide
How Much Epoxy Resin You Need for a Coating, River Table or Coasters
Work out epoxy volume from area times depth, split A/B from the maker's ratio, and stay inside each product's max layer. Includes a sourced product table.
Quick answer
Epoxy volume is the pour's area times its depth. A 1 m² coat 2 mm deep needs 2,000 mL of mixed epoxy before waste. Split that into Part A and Part B using the product's stated volume or weight ratio, and do not pour thicker than the maker's max layer in one go: coating epoxies are often around 6 mm per layer, while deep-pour products allow thicker lifts. The calculator on this page uses those figures from each product's data sheet.
Formula
V_mL = area_cm² × depth_cm | Part A / Part B from the volume (or weight) ratio | layers = ceil(depth ÷ max layer)
Accuracy
Reference table
Search by name or sort by any column. Each row links to the matching calculator.
6 of 6 rows · sorted by product
| Calculator | |||||
|---|---|---|---|---|---|
| ArtResin | Coating / topcoat | 1:1 | 1.05 | 3.175 mm (0.13 in) | Epoxy calculator |
| EcoPoxy FlowCast | Deep pour / river | 2:1 | 1.07 | 38 mm (1.5 in) | Epoxy calculator |
| EcoPoxy UVPoxy | Coating / topcoat | 1:1 | 1.07 | 3.2 mm (0.13 in) | Epoxy calculator |
| MAS Deep Pour X | Deep pour / river | 2:1 | 1.06 | 76.2 mm (3 in) | Epoxy calculator |
| TotalBoat TableTop | Coating / topcoat | 1:1 | 1.05 | 6.35 mm (0.25 in) | Epoxy calculator |
| TotalBoat ThickSet | Deep pour / river | 1:1 | 1.09 | 12.7 mm (0.5 in) | Epoxy calculator |
How it works
Volume from area and depth (coating, river and coasters)
Mixed epoxy volume in millilitres equals the pour area in square centimetres times the depth in centimetres (1 mL = 1 cm³). For a rectangular coat, area is length × width. For a river table, use the void area you measured (or approximate the river as a long rectangle and add a little). Coasters are the same formula on a small footprint; the calculator's coasters mode repeats it for a batch. Always add a waste allowance for mixing cups, brushes and the last bit that will not pour out cleanly.
Mix ratio by volume versus by weight
Most epoxy kits state a volume ratio (for example 1:1 or 2:1) and a density for the mixed liquid. Weighing parts is more accurate when the two sides have different densities: convert the volume split using each part's density, or use the maker's stated weight ratio when they publish one. The product table on this page shows both the volume ratio and the mixed density we took from each data sheet. Do not mix brands or substitute hardener from another kit.
Max layer depth, heat and multi-pour builds
Deep single pours can overheat as the resin cures. Each product lists a maximum layer thickness; coating epoxies are typically a few millimetres per coat, while deep-pour formulas allow thicker lifts for river voids. If your target depth exceeds the max layer, pour in stages and follow the maker's recoat window (often a few hours without sanding, longer if you miss it). The calculator counts how many layers you need from the product's max layer figure.
Work it out
Change the inputs to work out your own numbers. Each step of the working is shown with the answer.
Your measurements
Pick your epoxy and enter the size. Everything updates as you type.
Epoxy
A 1:1 coating epoxy for bar tops, tables and shallow castings, up to 1/4" per coat. Pour coats thicker than 1/4" as 1/4" layers at least 3 hours apart; no sanding needed between coats.
Surface
Coat
A flood coat is usually 1/8" (3 mm). Thicker coats go on in layers.
Common
10% covers the cup, stirrer and drips. Use 15–20% for live edges, bark and open grain that soak up epoxy.
Results
Total epoxy to mix
L
= 2.74 qt
Mixed volume with 10% extra for the cup and drips. Mix 1:1 by volume, 1.2:1 by weight.
- Part A (resin)
- 1.3L
- = 1.37 qt
- or 1.49 kg by weight
- Part B (hardener)
- 1.3L
- = 1.37 qt
- or 1.24 kg by weight
- Batch weight
- 2.73kg
- = 6.01 lb
- At 1.05 g/cm³
- Pours
- 1pour
- Up to 1/4" · 6.4 mm at once
Pour schedule
Pour coats thicker than 1/4" as 1/4" layers at least 3 hours apart; no sanding needed between coats.
| Pour | Fills to | Mix | Part A | Part B |
|---|---|---|---|---|
| 1 | 1/8" · 3.2 mm | 2.6 L | 1.3 L | 1.3 L |
How this was calculated
Area, volume, waste, the split and the layers, with your numbers.
How this was calculated
Area, volume, waste, the split and the layers, with your numbers.
Step 1: Area of the top
length × width
= 48″ (1219.2 mm) × 24″ (609.6 mm)
= 1,152 in²Measure the surface the epoxy will cover. Add the edges separately if you will let it run over them.
Step 2: Volume to fill
area × depth
= 1,152 in² × 0.125″ (3.2 mm)
= 2,360 mL (79.8 fl oz)1 cm³ is 1 mL, and 1 US fl oz is 29.57 mL.
Step 3: Add the waste allowance
volume × (1 + waste %)
= 2,360 mL (79.8 fl oz) × 1.1
= 2,596 mL (87.8 fl oz)Covers what stays in the cup and on the stirrer, drips over edges and soaks into wood. Seal-coat bare wood first so it does not drink the flood coat.
Step 4: Split by the volume ratio
Part A = total × 1 ÷ 2, Part B = total × 1 ÷ 2
= 2,596 mL × 1/2 and × 1/2
= A 1,298 mL (43.9 fl oz), B 1,298 mL (43.9 fl oz)TotalBoat TableTop mixes 1:1 by volume. Measure in graduated cups, then mix and transfer to a second cup.
Step 5: Weight of the batch
weight = volume × density; Part A = weight × 1.2 ÷ 2.2
= 2,596 mL × 1.05 g/cm³
= 2,725 g: A 1,487 g, B 1,239 gBy weight the ratio is 1.2:1, not 1:1, because the resin is denser than the hardener. Weighing is the more accurate way to measure.
Step 6: Layers
layers = ⌈depth ÷ thickest layer⌉
= ⌈0.125″ (3.2 mm) ÷ 0.25″ (6.4 mm)⌉
= 1 pourThe thickest layer is the maker's limit for one pour; thicker pours trap heat and can yellow, crack or ripple.
Sources
TotalBoat TableTop Epoxy: mix ratios, density and thickest pour
Checked against sourceChecked against the maker's documentation. Checked 24 Oct 2026.
- TotalBoat TableTop Epoxy Instruction Sheet and TDS (1A:1B by volume, 1.2A:1B by weight; resin 1.15 and hardener 0.95 g/cm³; max 1/4" per coat; small castings up to 1" deep and 6 fl oz per pour; do not mix more than one gallon at a time.), opened 24 Oct 2026
Average of the resin (1.15 g/cm³) and hardener (0.95 g/cm³) densities at 1:1 by volume. The data sheet also lists a cured density of 1.05 g/cm³.
Troubleshooting
What usually goes wrong, how to check for it, and how to prevent it.
The pour runs short before the surface is covered
- Cause
- Area or depth was underestimated, or waste was left at zero
- How to check
- Mixed volume used is well below area × depth
- Prevention
- Measure the void at several points, use the larger depth, and allow 10% or more for cups and brushes
The pour gets hot, yellow or cracks while curing
- Cause
- A single layer thicker than the product's max depth, or a large mass in a warm room
- How to check
- Layer depth above the data-sheet maximum, or a spike in surface temperature
- Prevention
- Split the pour into layers within the max depth, mix smaller batches and cool the room if the sheet says to
Soft or sticky patches after the stated cure time
- Cause
- Off-ratio mix, poorly scraped cups, or cold temperatures
- How to check
- Uncured spots where cups were poured out last, or room below the sheet's minimum
- Prevention
- Weigh or measure both parts carefully, scrape sides and bottom while mixing, and warm the room to the maker's range
Common questions
How much epoxy resin do I need for a table top?
Multiply the top's area by the coating depth. A 2 m × 0.8 m top coated 2 mm deep needs 3,200 mL of mixed epoxy before waste. Add your waste allowance, then split Part A and Part B from the product ratio.
How do I calculate epoxy for a river table?
Estimate the river void's area and average depth (or break it into simple shapes), convert to millilitres, add waste, and check the deep-pour product's max layer depth so you know how many lifts to plan. The river-table mode of the calculator does this from length, width and depth.
Should I mix epoxy by volume or by weight?
Follow the data sheet. If it gives a volume ratio, measuring cups are fine for small batches; weighing is more repeatable, especially when Part A and Part B have different densities. Use the maker's weight ratio when they publish one.
Can I pour a river in one go?
Only if the depth stays inside that product's maximum layer. Coating epoxies are not deep-pour products. If the void is deeper than the max layer, pour in stages and respect the recoat window on the sheet.