Hong Life CalculatorsUnderstanding the epoxy resin calculator — concept and principle
This calculator estimates how much mixed epoxy resin you need to coat a floor, flood-coat a tabletop or fill a river table, and how to split it between resin and hardener. Enter the area, the layer thickness, the density of the mixed resin and the mix ratio. It helps you buy the right kit size and measure each component accurately.
How it is calculated
- Mixed volume (L) = area (m²) × thickness (mm).
- Weight (kg) = volume × density (kg/L).
- Resin (kg) = weight × ratio ÷ (ratio + 1); hardener (kg) = weight ÷ (ratio + 1).
The ratio is entered as parts of resin per one part of hardener, so 2 means 2:1.
The principle
One square metre covered 1 mm deep holds exactly one litre (1 m × 1 m × 0.001 m = 0.001 m³), so area in m² times thickness in mm gives litres directly. Multiplying by density turns volume into weight; mixed epoxy is usually a little denser than water, often around 1.1 kg/L. A 2:1 ratio means the mixture is two thirds resin and one third hardener, so the total is divided into 3 parts.
Worked example
Default inputs: area 1.2 m², thickness 3 mm, density 1.1 kg/L, ratio 2:1.
- Volume = 1.2 × 3 = 3.6 L.
- Weight = 3.6 × 1.1 = 3.96 kg.
- Resin = 3.96 × 2 ÷ 3 = 2.64 kg.
- Hardener = 3.96 ÷ 3 = 1.32 kg.
| Area (m²) | Mixed volume (L) |
|---|---|
| 0.3 | 0.9 |
| 0.6 | 1.8 |
| 0.9 | 2.7 |
| 1.2 | 3.6 |
| 1.5 | 4.5 |
| 1.8 | 5.4 |
| 2.4 | 7.2 |
How to read the result
Floor coatings are often 1–3 mm, table flood coats 2–3 mm, and river table fills can be several centimetres deep. For a river table, enter the area of the channel only, not the whole table, and add extra for resin soaking into wood and leaking at the mould edges, often 10–15%. Check whether your product's ratio is given by weight or by volume: this calculator splits by weight, so for a volume ratio with components of different density the weights differ slightly. Deep-pour resins limit the thickness of each pour because curing releases heat.
Common mistakes
- Mixing by volume when the manufacturer specifies weight, or the reverse.
- Pouring thicker than the product's maximum, which can overheat and crack.
- Forgetting extra for sealing coats, edges and spills.
- Mixing a larger batch than can be poured within the working time.
Frequently asked questions
How much epoxy do I need per square metre?
About 1 litre per millimetre of thickness, roughly 1.1 kg at typical density.
Is the mix ratio by weight or by volume?
It depends on the product; the label states which. They are not interchangeable.
Why did my epoxy get hot and crack?
Curing is exothermic; a thick or large mixed batch can overheat. Use a deep-pour resin or pour in layers.
Sources: EN 13813 — Screed material and floor screeds: properties and requirements (includes synthetic resin screeds)