Resin art calculator

Art resins typically self-level at about 1/8 in (3 mm) on a flat surface; a thinner, spread-out coat uses far less. New to resin? Epoxy words explained covers kits, mix ratios and the rest in plain English.

How much resin a canvas takes

The math is area × thickness. A full 1/8 in coat over 1 sq ft is 18 cubic inches, which is almost exactly 10 fl oz (about 295 ml). That makes it easy to sanity-check any size: how much resin for a 12x12 canvas works out to about 10 fl oz before waste, because a 12 × 12 is exactly one square foot, and how much resin for a 16x20 canvas is about 22 fl oz before waste.

volume = length × width × thickness × (1 + waste)
1 sq ft at 1/8 in ≈ 10 fl oz
100 cm² at 3 mm = 30 ml

Why ArtResin’s guide says less

ArtResin’s own coverage guide says about 4 fl oz of mixed resin covers a square foot, and in the same breath that the resin self-levels at about 1/8 in. Those two figures don’t agree: 1/8 in over a square foot is about 10 fl oz, and 4 fl oz spread over a square foot is a coat of roughly 1/20 in (1.3 mm). In practice a thin, domed coat that stops at the edge uses far less than a coat that fully levels and runs over the sides. If you’re following a brand’s per-square-foot figure, pick the 1/16 in option for a close match; if you want the deep, glassy look (or you’re coating a textured painting), plan on 1/8 in.

Sides, drips and textured surfaces

Letting the resin run over the sides gives a finished edge, but a lot of it ends up on the drop sheet. The calculator counts the sides at the same thickness as the top to account for that runoff. On small pieces the sides are a surprisingly large share of the total — see how much resin for an 8x10 canvas — while on a big one like how much resin for a 36x48 canvas they are a smaller share but still a lot of extra ounces. Heavily textured paintings and open-weave canvases also take more than a smooth panel.

• Prop the canvas on cups or stands so drips fall clear, and tape the back to catch them.
• Stretched canvas sags under the weight of the resin; support it from underneath or use a cradled panel — how much resin for a 24x36 canvas shows how heavy that gets.
• Weigh parts A and B on a scale if your product gives a weight ratio — small batches are hard to measure accurately in cups.
• Mix slightly more than you need. Scraping the last few ounces out of a cup adds bubbles.

Mixing batches on big canvases

Mixed epoxy gives off heat as it cures (exotherm), and the heat speeds the reaction up. Epoxyworks, the WEST SYSTEM technical journal, explains that a big mass left in one container gets hot and thickens (gels) much faster than the same resin spread thin, and that mixing several smaller batches as you go is one way to keep your working time. ArtResin quotes about 45 minutes of working time for its resin; others differ, so check your label. The Largest batch setting under More options splits the total into batches — 48 fl oz (about 1.4 liters) by default; change it to whatever you can mix thoroughly and pour well inside your resin’s working time. How much resin for a 30x40 canvas walks through a two-batch pour.

Adding colour

Mica powder, pastes and liquid tints are measured as a percentage of the mixed resin, and most makers cap them at a few percent — too much can leave the coat soft or tacky. Weigh them rather than spooning them in: the epoxy pigment calculator turns a percentage into grams for each cup you mix.