Tabletop flood coat coverage calculator

How the calculator works

A flood coat is a thin, self-leveling layer poured over a flat surface. Its volume is the area it covers times its thickness. The calculator adds three things that often get forgotten: the edges, extra coats, and resin that never reaches the table.

Coating epoxies are made for this job. TotalBoat describes table top epoxy as clear and self-leveling, designed for flat surfaces, and recommends a seal coat plus one or two flood coats (TotalBoat). Because the resin levels itself, the surface must be level too, or the coat ends up thicker at one end.

Formula and assumptions

V = (A_top + P × h_edge) × t × coats × (1 + loss %)

• A_top is length × width for a rectangle, or π × (D/2)² for a round top.
• P × h_edge is the edge area: perimeter times the height of the edge you want coated. Leave the edge height at 0 to coat the top only.
• t is the thickness of one coat. Use the figure from your product’s data sheet.
• Edges are counted at the same thickness as the top. In practice resin runs off vertical edges and leaves a thinner film, so this slightly overestimates. That is the safe direction for buying resin.
• Mixing loss and drips default to 10 %. This is an assumption, not a manufacturer figure.

Theory against the label

One US gallon is exactly 231 in³ (NIST Handbook 44, Appendix C). Spread 1/8 in thick, it covers 231 ÷ 0.125 = 1,848 in², which is 12.83 ft². In metric, 1 litre at 1 mm covers exactly 1 m².

TotalBoat’s table top guide says a gallon of table top epoxy covers approximately 12 ft² at 1/8 in (TotalBoat). The gap between 12.8 and 12 ft² is about 6.5 %. TotalBoat does not say what the margin is for; resin left in the cup and on the spreader is one plausible reason. The calculator’s loss factor is where you account for that kind of loss, and you can set it to match your own experience.

Worked example

A 48 × 30 in desk top, one flood coat at 1/8 in, top only, 10 % loss.

1. Area: 48 × 30 = 1,440 in² (10 ft²).
2. Volume: 1,440 × 0.125 = 180 in³ = 0.78 gal (2.95 L).
3. With 10 % loss: 0.78 × 1.1 = 0.86 gal (3.24 L).

Coat the 3/4 in edges as well and the edge area adds 2 × (48 + 30) × 0.75 = 117 in², about 8 % more resin.

Tips

• Seal coat first. A thin seal coat on bare wood reduces the air that escapes from the grain into the flood coat. Size it by setting a smaller thickness.
• Two coats are two pours. Check the data sheet’s recoat window before planning the second one; the temperature and timing helper lists it for products in our database.
• Small pieces need proportionally more resin for their edges, because the perimeter is long relative to the area. Coat the edges in the calculator to see the difference.