From measurements to epoxy purchase quantity: three worked examples.
The calculations below use illustrative project dimensions, not invented job-site measurements. They show the inputs and arithmetic so you can reproduce each answer, change an assumption and spot a common mistake before buying a kit.
An estimated volume does not establish whether a particular resin is technically suitable. Always follow the current manufacturer instructions for mixing, pour depth, coating application, temperature and cure.
Before calculating: what to measure
| Project | Measurements you need | Important extra check |
|---|---|---|
| Floor coating | Actual coated area in m²; planned wet thickness in mm | Manufacturer coverage per coat and substrate porosity |
| River table | River length; widths at equal intervals; average pour depth | Voids, sealing and the product's allowable layer depth |
| Deep casting | Internal cavity length, width and depth | Maximum single pour depth at your batch size and temperature |
Write your measurements down before entering them into a calculator. Keep the raw geometry result separate from any material-loss allowance. For mixed products, check whether the manufacturer's kit quantity is total mixed volume or the weight of the individual components.
Example 1 — 18 m² epoxy floor at 0.4 mm wet thickness
The floor area is 18 m². The illustrative coating thickness is 0.4 mm, which makes theoretical wet consumption 0.4 litres per square metre. Unlike a manufacturer's product coverage figure, this is a geometry-only calculation and does not account for solids content, texture or absorption.
| Area | 18 m² |
|---|---|
| Wet thickness | 0.4 mm |
| Raw volume | 18 × 0.4 = 7.20 L |
| Illustrative 10% allowance | 7.20 × 0.10 = 0.72 L |
| Planning quantity | 7.92 L |
If the product requires two coats, calculate the coats separately using their specified application rates rather than assuming the same total thickness. A 5-litre kit by itself is not enough for the illustrative 7.92 L wet-volume requirement; check the complete manufacturer kit basis and available package sizes.
Run your measurements in the floor coverage calculator →
Example 2 — irregular river table with five width measurements
A river channel is 1.80 m long, and the widths measured at five evenly spaced points are 100, 140, 190, 130 and 90 mm. Its assumed depth is 35 mm. Instead of multiplying its maximum width by the full length, the river calculator estimates four trapezoidal sections.
| Section | Adjacent widths | Average width | Length |
|---|---|---|---|
| 1 | 100 + 140 mm | 120 mm | 450 mm |
| 2 | 140 + 190 mm | 165 mm | 450 mm |
| 3 | 190 + 130 mm | 160 mm | 450 mm |
| 4 | 130 + 90 mm | 110 mm | 450 mm |
The plan area is (120 + 165 + 160 + 110) × 450 = 249,750 mm². Multiply by 35 mm depth to get 8,741,250 mm³, or 8.74 L. With an illustrative 10% allowance, the planning quantity is 8.74125 × 1.10 = 9.62 L (rounded). This estimate assumes a consistent depth between the points; large voids, uneven bottoms and seal coats need additional measurement.
Enter your own width points in the river table calculator →
Example 3 — a rectangular 1.20 × 0.30 × 0.04 m deep pour
Convert to millimetres first: 1,200 × 300 × 40. Raw volume is 14,400,000 mm³, or 14.40 L. Using a hypothetical 12% waste allowance produces 14.40 × 1.12 = 16.128 L.
Suppose the chosen product's technical sheet specifies a 2:1 ratio by volume. In that specific case, 16.128 L of total mixture divides into 10.752 L resin and 5.376 L hardener. Do not apply this volume split to a product labelled 2:1 by weight; resin and hardener densities may be different.
Purchase planning is a separate step: two hypothetical 8 L complete kits total 16 L and would be short by 0.128 L. Two 10 L complete kits total 20 L, leaving 3.872 L of nominal excess. This is only a packaging illustration, not a current stock or price claim.
Finally, the 40 mm cavity depth is not proof the selected epoxy may be cast 40 mm in one pour. Check the current manufacturer depth limit for project dimensions and ambient temperature.
Calculate a deep pour and check compatible products → Then use the resin and hardener ratio calculator with the ratio printed on your actual kit.
Five checks that prevent expensive estimating mistakes
- Do not use the outer table dimensions for a narrow river channel; measure the channel itself.
- Keep metres, millimetres, inches and US gallons explicit. Never mix them in one multiplication.
- Use wet-film thickness for a theoretical volume calculation, not an assumed dry-film thickness.
- Use manufacturer density before turning kilograms into litres; 1 kg is not automatically 1 L.
- Before ordering, separately verify mix-ratio basis, cure guidance, kit contents and maximum pour depth.
What these examples can and cannot tell you
They teach transparent quantity planning and unit conversions. They cannot certify the quality of a substrate, guarantee real consumption, establish a product's safe exotherm limit or predict current retail prices. See the calculation methodology for implementation details and the manufacturer-sourced product database for published system-specific specifications.
Illustrative examples prepared and checked against EpoxyCalc's published geometric formulas · 4 October 2026.