Epoxy coverage chart: square feet per gallon at every thickness

The one formula behind every row

A gallon of mixed epoxy is 231 cubic inches (the US definition, from NIST Handbook 44). Spread it into a layer and the area it covers is that volume divided by the thickness. Divide by 144 to turn square inches into square feet:

square feet per gallon = 231 ÷ (thickness in inches × 144)
square meters per liter = 1 ÷ thickness in mm
floor coatings: square feet per gallon = 1,604 × solids ÷ mils

Everything in this guide is theoretical coverage: the area a gallon covers if every drop ends up on the surface at exactly that thickness. Real jobs lose some to the mixing bucket, the stir stick, drips off the edges and wood that soaks it up — so divide the area you need by these figures, then add a waste allowance (10–15% for most coats).

Square feet per gallon, 1/32 in to 1 in

Two rows are worth remembering. At 1/8 in — the thickness most tabletop epoxies level out at on their own — a gallon covers 12.8 sq ft, which matches the coverage TotalBoat prints for its 1-gallon TableTop kit. At 1/16 in it covers twice that, 25.7 sq ft. Anything past 1/4 in is usually no longer a coating job: check the maximum depth per pour on your label before you plan it as one. A seal coat is thinner than all of these: a seal coat ≈ 1–2 fl oz per sq ft (0.3–0.6 L/m²), more on spalted or end grain.

Square meters per liter, by millimeter

Metric is simpler, because 1 liter spread 1 mm thick covers exactly 1 square meter. So the coverage in m² per liter is just 1 divided by the thickness in millimeters, and the liters you need per m² is the thickness itself.

That 2 m² example is the 200 × 100 cm table top worked in full, including the drip allowance.

Ounces per square foot (for small pieces)

Resin art and small crafts are easier to plan in fluid ounces or milliliters per square foot. One square foot at 1/8 in is 18 cubic inches, which is almost exactly 10 fl oz:

Some resin brands quote smaller figures — ArtResin’s rule of thumb is about 4 oz of mixed resin per square foot, for example. By the arithmetic that is closer to a 1/20 in coat than a full 1/8 in one; it works on a smooth, flat surface, but a textured painting or a coat you want to look deep takes more. For a 12 × 12 in canvas (exactly one square foot), the 12 × 12 canvas example shows both figures side by side.

Floor coatings by mils

Floor coatings go on far thinner than table coats, so they are measured in mils — thousandths of an inch. A gallon spread 1 mil thick covers 231 ÷ 0.001 ÷ 144 ≈ 1,604 sq ft. Divide 1,604 by the thickness in mils for any other film. That assumes a 100%-solids product, where everything in the can stays on the floor; a product that is partly water or solvent leaves a thinner dry film, so multiply by its solids fraction (from the data sheet) first.

So a two-car garage of 400 sq ft at 10 mils needs 400 ÷ 160 = 2.5 gallons per coat before waste — the 400 sq ft at 10 mils example adds the waste allowance and a second coat, and the metric 50 m² floor does the same in liters. Boxed garage kits are sold by coverage instead of by the gallon; the garage floor calculator handles those.

Using the chart: three quick examples

• A 4 × 8 ft table top at 1/8 in: 32 sq ft ÷ 12.8 = 2.5 gallons before drips. The 4 × 8 table top example adds what drips off its 24 ft of edge and the film left on the sides — about 2.93 gallons in all, which makes three 1-gallon kits too tight a fit.
• A 36 in round table at 1/8 in: π × 18² = 1,018 sq in, or 7.07 sq ft; 7.07 ÷ 12.8 = 0.55 gallons before drips — the 36 inch round table example takes it from there.
• A 30 sq ft countertop, seal coat plus flood coat: 30 ÷ 25.7 + 30 ÷ 12.8 ≈ 3.5 gallons if the seal coat were a full 1/16 in — but a seal coat is scraped on far thinner, about 1–2 fl oz per sq ft, which is 0.23–0.47 gallons on 30 sq ft. The 30 sq ft countertop example works the full job, with the seal coat as a variant.

Why real coverage is lower than the chart

• Edges. A flood coat runs over every edge and keeps dripping. Small tops lose a bigger share this way.
• Absorption. Bare wood, concrete and paper soak up resin. That is what a seal coat is for.
• Texture. Bottle caps, coins, a textured painting or a rough concrete profile all add surface area.
• The cup. Some resin always stays in the mixing bucket and on the stick — a bigger share of a small batch.
• Kit naming. A “1 gallon kit” normally means 1 gallon mixed, but some are sold by the size of each part. Check the combined volume.

A calculator for every project

The chart is the quick answer; each calculator below does the same math for its own project, rounds up to whole kits and shows its working:

• Tables and furniture: river table, tabletop, bar top, countertop.
• Floors: garage floor kits and floor coating by the gallon.
• Art and small pieces: resin art, coasters, tumblers, resin molds, silicone molds.
• Boats and composites: fiberglass and epoxy — cloth is sized by weight, not thickness; see how much epoxy to fiberglass a 4×8 sheet of plywood.
• Any shape: the epoxy resin calculator, plus the mix ratio, volume to weight, cost and cure time calculators.