Epoxy Calculator
Work out how much epoxy resin you need for a tabletop, river table, countertop or garage floor. Enter the size, pour depth, epoxy type, mix ratio and waste allowance, and get gallons and fluid ounces, the resin and hardener split, number of pours, kits to buy and an estimated cost — with depth and kit-size comparisons, a chart and a downloadable PDF.
| Depth | Epoxy + waste | Pours | Kits | Epoxy cost |
|---|---|---|---|---|
| Enter your project size to compare | ||||
| Kit size | Kits | Gallons bought | Leftover | Epoxy cost |
|---|---|---|---|---|
| Enter your project size to compare | ||||
How to use the epoxy calculator
Four quick steps turn your project size and pour depth into gallons of epoxy, resin and hardener amounts, number of pours, kits to buy and cost — with by-depth and by-kit tables, a chart and a downloadable report.
Pick a project
Choose tabletop, river table, countertop or garage floor to load typical settings — you can change any of them.
Enter the size
Give the length and width (or diameter) in inches or feet, the number of pieces and the share of the area that is epoxy.
Set depth, type & kit
Choose the pour depth, coating, medium or deep-pour epoxy, the mix ratio, waste and your kit size and price.
Read results & save a PDF
Get gallons, ounces, resin and hardener, pours, kits, leftover and cost — then download a report.
How much epoxy you need
Epoxy is a volume: area times depth. One US gallon is 231 cubic inches, so the math converts cubic inches to gallons and adds a waste allowance. Here is the exact math the calculator runs.
Worked example — 48 × 30 in tabletop, 1/8″ flood coat, coating epoxy 1:1, 10% waste, 1 gal kits at $65
Area: 48 × 30 = 1,440 sq in (10 sq ft) · Volume: 1,440 × 0.125 = 180 cu in
Gallons: 180 ÷ 231 ≈ 0.78 gal × 1.10 ≈ 0.86 gal (110 fl oz) · Mix: 0.43 gal resin + 0.43 gal hardener
Pours: 1 · Coverage: 231 ÷ (144 × 0.125) ≈ 12.8 sq ft/gal · Kits: 1 × 1 gal (0.14 gal left) · Cost: $65 + $15 supplies = $80
≈ 0.86 gallons — one 1 gallon kit in a single pour, about $80 or $8.00 per sq ft.
Epoxy reference charts
Handy lookups for how depth changes the amount and the number of pours, typical project quantities, and which kit size fits best.
| Depth | Epoxy + waste | Coverage | Pours: coating · medium · deep |
|---|---|---|---|
| 1/8″ | 0.86 gal | 12.8 sq ft/gal | 1 · 1 · 1 |
| 1/4″ | 1.71 gal | 6.4 sq ft/gal | 2 · 1 · 1 |
| 1/2″ | 3.43 gal | 3.2 sq ft/gal | 4 · 1 · 1 |
| 1″ | 6.86 gal | 1.6 sq ft/gal | 8 · 2 · 1 |
| 1-1/2″ | 10.3 gal | 1.1 sq ft/gal | 12 · 3 · 1 |
| 2″ | 13.7 gal | 0.8 sq ft/gal | 16 · 4 · 1 |
Doubling the depth doubles the epoxy. For pours over 1/8″, a medium or deep-pour resin saves many layers.
| Project | Size & depth | Epoxy + waste | Kits · cost |
|---|---|---|---|
| Tabletop | 48 × 30 in · 1/8″ | 0.86 gal | 1 × 1 gal · $80 |
| River table | 72 × 36 in, 30% epoxy · 1-1/2″ | 5.81 gal | 2 × 3 gal · $580 |
| Countertop | 96 × 25.5 in · 1/8″ | 1.52 gal | 2 × 1 gal · $155 |
| Garage floor | 20 × 20 ft · 20 mils | 5.49 gal | 2 × 3 gal · $390 |
Waste is 10% for the tabletop and floor and 15% for the river table and countertop. Costs include example supplies.
| Kit size | Kits | Gallons bought · leftover | Epoxy cost |
|---|---|---|---|
| 1 qt | 4 | 1.00 · 0.14 gal | $65 |
| 1 gal | 1 | 1.00 · 0.14 gal | $65 |
| 2 gal | 1 | 2.00 · 1.14 gal | $130 |
| 3 gal | 1 | 3.00 · 2.14 gal | $195 |
At $65 per mixed gallon. Kit size is the total of resin plus hardener — a “1 gallon kit” is usually a half gallon of each for 1:1 epoxy.
What the epoxy calculator gives you
Your project size and pour depth become a full mixing and buying plan.
Epoxy at a glance
Who uses an epoxy calculator
From a coffee table flood coat to a full garage floor, the same calculator tells you how much to buy.
Pouring a river table or a tabletop flood coat and needs gallons, the resin / hardener split and how many pours.
- Set the epoxy share %
- Use deep-pour resin
- Seal the wood first
Coating countertops or a bar top and wants enough epoxy to flood the edges without running short.
- Use 15% waste
- Pick 1/8″ depth
- Compare kit sizes
Rolling epoxy onto a garage floor and needs gallons for a coating measured in mils.
- Enter size in feet
- Use 0.02″ for 20 mils
- Buy larger kits
Tips for a clean epoxy pour
Epoxy is unforgiving — these habits help you get a clear, bubble-free, fully cured finish.
Epoxy calculator FAQ
Quick answers about how much epoxy you need, coverage, pour depth, mix ratio, river tables and garage floors.
Multiply the area in square inches by the pour depth in inches, then divide by 231 to get gallons. A 48 × 30 inch tabletop at 1/8 inch is 1,440 × 0.125 = 180 cubic inches, or about 0.78 gallons.
Add 10% for waste and you need about 0.86 gallons (110 fl oz) — one 1 gallon kit.
At 1/8 inch deep, one gallon covers about 12.8 sq ft. Coverage is 231 ÷ (144 × depth in inches).
At 1/4 inch it covers about 6.4 sq ft, and at a 20-mil garage floor coating about 80 sq ft.
It depends on the type. Coating (table-top) epoxy is usually poured up to about 1/8 inch per layer, medium-pour resin about 1/2 inch, and deep-pour casting resin about 2 inches.
A 1 inch pour takes 8 layers of coating epoxy, 2 of medium or 1 of deep-pour. Always check your product’s label.
Multiply the slab area by the share that is epoxy, then by the depth. A 72 × 36 inch table that is 30% river at 1-1/2 inches deep needs about 5.05 gallons, or 5.81 gallons with 15% waste.
With a 2:1 deep-pour resin that is about 3.87 gallons of resin and 1.94 gallons of hardener — two 3 gallon kits.
Divide the total by the ratio parts. For 1:1, use half resin and half hardener. For 2:1, use two-thirds resin and one-third hardener.
Mix exactly the ratio on your kit, by volume — off-ratio epoxy may never fully cure.
Garage floor coatings are measured in mils, where 1 mil is 0.001 inch. Two 10-mil coats is 0.02 inch, which covers about 80 sq ft per gallon.
A 20 × 20 ft garage (400 sq ft) at 20 mils needs about 4.99 gallons, or 5.49 gallons with 10% waste.
Add about 10% for drips, mold leaks and what stays in the mixing bucket. Use 15% for flood coats that run over the edges or live-edge slabs, and 20% for your first pour.
Running short mid-pour is far worse than having a little left over.
Coating epoxy often costs about $50 to $100 per mixed gallon, deep-pour resin about $70 to $150, and garage floor epoxy about $40 to $90.
A 48 × 30 inch tabletop at $65 per gallon needs one 1 gallon kit — about $80 with $15 of supplies, or $8.00 per sq ft.
Planning aid only — follow your product’s label. This calculator works in US units (inches, feet, US gallons) and uses 231 cubic inches per gallon and about 9.2 lb per mixed gallon. Maximum layer depth, mix ratio and cure times vary by brand, so never pour thicker than your product allows. Seal porous wood first, add waste for drips and leaks, and work with gloves, eye protection and good ventilation. Prices are examples only.