Epoxy coverage calculator

How far a gallon goes at your own coat depth, and how many kits that is to buy, because coverage halves every time the depth doubles, and no printed coverage figure means anything without one beside it.

INPUTS
The glossy coating one. Built to be poured thin over a surface and self-level into a hard, clear film, bar tops, counters, artwork, tumblers. It is fast, and the speed is the point: a coat is dust-free in a few hours instead of a few days.
The surface
sq ft
Edges and a backsplash are extra area and real resin, add them in.
in
1/8 in, 3.17 mm. An eighth of an inch per flood coat. That is not a suggestion about finish quality, a table top system reaches its peak reaction temperature in twenty minutes or so, and depth is what decides whether that heat can escape into the room or stays trapped in the middle of the pour. Build up thickness with several coats, letting each one firm up first.
A second coat doubles the resin. It does not double the depth of the first.
%
What stays in the cup, runs off the edges and gets skimmed with the bubbles. Roughly what the printed coverage figure already has folded into it.
A coverage figure is arithmetic, not permission. 1/8 in is what table top / coating epoxy takes in one pour, and covering an area more thinly than that is always safe while covering it more thickly is not.
RESULTS
One gallon covers
12.8 sq ft
at 1/8 in 6.4 sq ft at twice the depth 25.7 sq ft at half
This job
FigureAmount
Area 10.0 sq ft
One coat 0.78 US gal
All 1 coat, with wastage 0.86 US gal
Pours it has to be split into 1 pour
Gallons for the job
0.86US gal
Printed on the tin
12sq ft at 1/8 in
Coverage halves every time the depth doubles, which is why a figure quoted without a depth beside it means nothing. The geometry gives 12.8 square feet per gallon at an eighth of an inch and the tin says 12, the gallon has not shrunk, the printed figure has about 6% of waste allowance already folded into it for what stays in the cup and runs off the edges.

How this is worked out

Coverage is geometry and this page refuses to treat it as a lookup: one square centimetre poured one millimetre deep is 0.1 ml, exactly and always, and everything else is unit conversion. So the area is worked out in square feet, converted to square centimetres, multiplied by the coat depth and by the number of coats, and the wastage allowance is added on top, then divided into US gallons, because that is what a shopping list is written in. Read backwards, the same sum gives what a gallon covers at any depth, which is the figure printed on a tin. Two things follow from it that are worth saying plainly. Coverage HALVES every time the depth doubles, so a coverage number quoted without a depth beside it is not a fact. And the geometry disagrees with the tin, 12.8 square feet against 12 at 1/8 in, because the printed figure already has roughly 6% of waste allowance inside it.

ml = area_cm² × depth_mm × 0.1 exact, always
sq ft/gal = 3785 ÷ (depth_mm × 0.1) ÷ 929.03
buy = ceil(ml needed ÷ pack ml) you cannot buy 1.3 of a kit
1/8 in → 12.8 sq ft/gal · 1/4 in → 6.4 · 1 in → 1.6
tin says 12, the gap is ~6% waste allowance

Questions makers ask

How many square feet does a gallon of epoxy cover?
About 12.8 square feet at 1/8 in, which is the depth almost every coverage figure is quietly quoting. At 1/4 in it is 6.4, and at 1 in it is 1.6. Coverage halves every time the depth doubles, so the number is meaningless without a depth attached to it, which is the single commonest way a project runs short.
Why does the tin say 12 square feet and the calculator says more?
Because the printed figure has a waste allowance folded into it. One US gallon spread 1/8 in deep is 12.8 square feet by geometry; the tin says 12, which is about 6% less. The gallon has not shrunk, that difference is what stays in the cup, runs off the edges and gets skimmed off with the bubbles. This site's own default allowance is 10%, a little more generous, because you cannot go back for more once a pour has started.
How much epoxy do I need per square foot?
295 ml at 1/8 in, and it scales straight with depth, one square centimetre poured one millimetre deep is 0.1 ml, exactly and always. Everything else on this page is that sum plus unit conversion.
How much epoxy for a countertop?
The kitchen counter, 10 ft preset works out at 6.8 litres, or 1.79 US gallons, for one flood coat with wastage, so 2 gallon kits on the shelf. Add the edges and any backsplash separately: they are real area and resin runs off them. <a href="/epoxy-countertops">The countertop guide</a> covers the rest of the job.
Does a second coat double the resin?
It doubles the resin and it does not double the depth of the first, which is worth being clear about because the two get confused. Two 1/8 in coats use the same resin as one 1/4 in pour and are safe where the single pour is not, table top / coating epoxy tops out at 1/8 in in one go. Depth is a heat limit, not a finish preference.
How many kits should I buy?
Enough to finish in one pour, rounded up to a whole pack. Running out halfway leaves a visible cold-join line that cannot be sanded out, and pot life is measured in tens of minutes on a coating system, there is no going back to the shop. The tool rounds up for you across the sizes the craft is actually stocked in, from a 0.5 L starter kit to a 11 L one.
What is epoxy coverage per gallon at 1/4 inch?
6.4 square feet, half the 1/8 in figure. But 1/4 in is already past what table top / coating epoxy takes in one pour, so at that depth the question is not only how far a gallon goes, it is whether you should be using a coating epoxy at all, or deep pour / casting epoxy, which goes to 2 in in one lift.
Is coverage different for deep pour epoxy?
No. Coverage is pure geometry and it does not know what is in the bottle, a litre of anything fills a litre of space. What changes between the systems is how much of that depth you may lay down at once, and <a href="/deep-pour-vs-table-top-epoxy">that difference</a> is a thermal limit rather than a coverage one.

Coverage at every depth people actually pour

One gallon, six depths. Each row halves the one above it, which is the whole behaviour of this number, and the last column is the constraint nobody quotes alongside coverage: past 1/8 in a coating epoxy is the wrong product, however far the gallon goes.

Coat depth One gallon covers Per square foot In one pour, that is
1/16 in 25.7 sq ft 147 ml Table top
1/8 in 12.8 sq ft 295 ml Table top
1/4 in 6.4 sq ft 590 ml Deep pour
1/2 in 3.2 sq ft 1180 ml Deep pour
1 in 1.6 sq ft 2360 ml Deep pour
2 in 0.8 sq ft 4719 ml Deep pour

The trade figure of 12 square feet a gallon sits against 12.8 in the second row. Both are right: one is the geometry and the other is the geometry with a waste allowance already in it. Use whichever you like, and do not add your own allowance twice.

Read before your next batch

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