How it works
The calculator multiplies the area of the top by the depth of the pour, converts the volume to gallons, ounces or litres, and divides by the kit size. It also divides the depth by the product’s maximum pour depth to show how many layers are needed.
Area = Length × Width or π × Diameter² ÷ 4 or entered area
Volume = Area × Depth × (1 + Extra ÷ 100)
Kits = ⌈ Volume ÷ Kit volume ⌉
Pours = ⌈ Depth ÷ Maximum depth per pour ⌉
⌈ ⌉ rounds up to a whole number. 1 US gallon = 231 cubic inches = 128 fluid ounces = 3.785 litres.
Worked example in words
A 6 × 3 ft tabletop is 72 × 36 = 2,592 sq in, or 18 sq ft. A 1/8 in flood coat takes 2,592 × 0.125 = 324 cubic inches. Divided by 231, that is 1.40 gallons, so two 1 gallon kits of TotalBoat TableTop. The coat is within TableTop’s 1/4 in per coat, so it goes on in one pour.
Maximum pour depth by product
Epoxy heats up as it cures, and a layer that is too thick can overheat. The TotalBoat data sheets give TableTop 1/8–1/4 in per coat, ThickSet 1/2 in per coat on tables and rivers (2 in only for small castings up to 10 fl oz), and Fathom up to 2 in per pour for river tables and slabs, but not less than 1 in. Thicker builds are poured in layers, each allowed to cool before the next; the volume does not change.
Kit sizes
TotalBoat sells TableTop in 1/2, 1 and 2 gallon kits, ThickSet in 8 oz, pint, quart and 1 gallon kits, and Fathom in 1.5, 3 and 6 gallon kits. Kit sizes here are the mixed volume of resin and hardener. For other brands, enter the kit volume and maximum pour depth from the product’s data sheet. This calculator is for tables, counters and castings; for a garage or basement floor, use the epoxy floor calculator.
Worked example
Inputs
- Shape
- Rectangle (length × width)
- Length
- 6 ft
- Width
- 3 ft
- Pour depth or coat thickness
- 1/8 in
- Epoxy
- TotalBoat TableTop (coatings, up to 1/4 in per coat)
- Kit size
- 1 gallon kit (2 half gallons)
- Extra allowance
- 0 %
Result
- Surface area
- 18 sq ft
- Epoxy needed
- 1.4 gal (179.5 fl oz, 5.61 qt)
- Kits to buy
- 2
- Maximum depth per pour
- 0.25 in
- Pours (layers)
- 1
Common mistakes
- Pouring a coating epoxy too deep. TableTop epoxy is applied 1/8–1/4 in per coat; poured deeper, it can overheat, crack or yellow. Deep pours need a deep-pour epoxy or several layers.
- Counting the bottles, not the mixed volume. A 1 gallon kit holds two half-gallon bottles – one gallon once mixed.
- Forgetting what runs over the edges. A flood coat drips down the sides of a tabletop; add extra or count the edge area.
- Mixing too much at once. A large batch heats up in the cup and sets before it is poured.
- Measuring the river at its widest point. Use the average width of the gap, or split the river into sections.
Assumptions and limits
- The pour is a flat layer of even depth over a rectangle, a circle or the area you enter.
- Kit sizes are the mixed volume of resin and hardener from the TotalBoat data sheets; shrinkage during the cure is not included.
- The number of pours is the depth divided by the product’s maximum pour or coat depth, rounded up.
- Edges, seal coats, absorption into the wood and leftovers in the cups are covered only by the extra allowance.
- Mold, dam tape, release agent, sanding and finishing are not included.
Frequently asked questions
How much epoxy do I need for a table top?
Multiply the length by the width by the thickness and convert to gallons – 231 cubic inches make one gallon. A 6 × 3 ft table with a 1/8 in flood coat is 72 × 36 × 0.125 = 324 cubic inches, or 1.4 gallons, which is two 1 gallon kits.
How much epoxy for a river table?
Multiply the length of the river by its average width and its depth. A 6 ft river 8 in wide and 1 1/2 in deep is 864 cubic inches, about 3.7 gallons – three 1.5 gallon kits of a deep-pour epoxy such as TotalBoat Fathom.
How many square feet does a gallon of epoxy cover?
At 1/8 in thick, one gallon covers 231 ÷ 0.125 = 1,848 sq in, about 12.8 sq ft – the figure TotalBoat gives for TableTop. At 1/4 in it covers half as much.
How deep can I pour epoxy in one layer?
It depends on the product. TotalBoat gives 1/8–1/4 in per coat for TableTop, 1/2 in per coat for ThickSet and up to 2 in per pour for Fathom on river tables. Thicker builds are poured in layers.
How many ounces of epoxy are in a gallon?
128 US fluid ounces. Small projects are easier to measure in ounces; the result shows both.
Sources
- TotalBoat TableTop Epoxy – Technical Data Sheet and Instructions (03.08.22) — TotalBoat (Jamestown Distributors). Units "2-Quarts, 2-Half-Gallons, 2-Gallons" (kits of 1/2, 1 and 2 gal mixed); "12.8 sq. ft. @ 1/8" per mixed gallon"; "Do not apply TableTop Epoxy thicker than 1/8" - 1/4" per coat" – step-pour thicker coatings; "Do not mix more than one gallon at a time."
- TotalBoat ThickSet Epoxy – Technical Data Sheet (03.05.25) — TotalBoat (Jamestown Distributors). Unit sizes: 8 Ounce Kit, Pint Kit, Quart Kit, 1 Gallon Kit (2 half-gallon bottles), 1A:1B; "Do not apply ThickSet thicker than ½" per coat" (up to ½" deep for river tables); small castings "maximum pour depth of 2" — using a maximum amount of 10 fluid ounces"; flood coat of ½": 3.2 sq ft per 1-gallon kit; seal coat roughly 24 sq ft.
- TotalBoat Fathom Deep Pour Epoxy – Technical Data Sheet (02.12.25) — TotalBoat (Jamestown Distributors). Units: 1.5 Gallon Kit, 3 Gallon Kit, 6 Gallon Kit; river tables and slabs "do not exceed a pour depth of 2""; small molds (up to 1 mixed gallon) up to 3" deep; "do not use Fathom for pours less than 1" in depth"; "231 cubic inches per gallon of mixed Fathom".
- NIST Handbook 44, Appendix C – General Tables of Units of Measurement — National Institute of Standards and Technology. Exact unit definitions: 1 in = 2.54 cm, 1 yd³ = 27 ft³, 1 US gal = 231 in³, 1 lb = 0.45359237 kg.
Method reviewed November 6, 2026