Epoxy Resin Calculator
Find how much epoxy resin you need for a pour, from the surface area and depth.
Reviewed by the ToolNestr Editorial Team — July 2026
How the epoxy resin calculator works
Epoxy resin volume follows straightforward geometry: multiply the surface's length by its width by the pour depth to get cubic inches, then convert to fluid ounces using the fact that one cubic inch holds about 0.554 fluid ounces. This works for any flat pour — a tabletop coating, a river table fill, or a floor topcoat — as long as you know the area and how thick a layer you're pouring.
Depth matters beyond just the material quantity: standard tabletop epoxy is formulated for thin pours, usually limited to about 1/8 to 1/4 inch at a time, because a thicker single pour traps more curing heat and can crack, yellow, or cloud as a result. Deep-pour epoxy formulations are chemically different, designed to cure slower and cooler, and can often go 1 to 2 inches or more in a single pour — always check the specific product's rated maximum depth rather than assuming.
Because some resin is inevitably lost in mixing cups, on stir sticks, and to minor drips over an edge, a 10 to 15% overage is standard practice on top of the calculated volume — this tool defaults to 10%, adjustable for a particularly involved pour. For anything beyond a single thin coat, plan on multiple pours with standard epoxy rather than exceeding its safe single-pour depth.
Maximum pour depth and mix-ratio guidance follow manufacturer technical data sheets typical of major epoxy resin brands.
Measure the surface
Length and width in inches.
Set the pour depth
Check it's within your epoxy's rated max.
Buy with overage
10-15% extra for mixing loss.
The formula explained
Volume
= L × W × depth. A 36×24 in table, 0.125 in deep: 864 × 0.125 = 108 in³.
Fluid ounces
= in³ × 0.554 = 108 × 0.554 = 59.8 fl oz.
With overage
× 1.10 = 59.8 × 1.10 = 65.8 fl oz to buy.
Worked example
A 48×30 in bar top, poured 1/4 inch deep, 15% overage.
Where this calculator gets used
River tables
Filling the "river" gap between two live-edge wood slabs is the classic deep-pour application, often 3/4 to 1+ inch deep and requiring a deep-pour formulation rather than standard tabletop epoxy.
Bar and countertop coating
A thin 1/8 to 1/4 inch clear topcoat over a bar, countertop, or dining table protects the surface while showcasing wood grain, pigments, or embedded objects underneath.
Resin art and coasters
Small-format resin art, coasters, and jewelry molds use tiny volumes, often under an ounce, where getting the mix ratio and overage right matters more than the raw calculation.
Garage and industrial floor coatings
Large floor areas use a thin, self-leveling epoxy coat, so total volume is driven mostly by square footage rather than depth — buying in gallon quantities makes sense at this scale.
Real-world context
A 60 in by 30 in river table with a 1 inch deep pour needs 1,800 cubic inches of resin. Converted at 0.554 fluid ounces per cubic inch and with a 10% overage, that comes to about 1,097 fluid ounces — roughly 8.6 gallons. A pour this deep and this large absolutely requires a deep-pour epoxy formulation, since standard tabletop epoxy poured this thick would generate enough exothermic heat during cure to crack or discolor.
At the opposite extreme, a small 4 in by 4 in coaster poured 1/4 inch deep needs only 4 cubic inches of resin. With a 15% overage that's about 2.5 fluid ounces — less than a shot glass — which is why small resin art projects are usually measured and mixed in small disposable cups rather than by the gallon.
A 120 in by 96 in garage floor (10 ft by 8 ft) coated at a thin 1/8 inch needs 1,440 cubic inches, which works out to about 878 fluid ounces, or roughly 6.9 gallons with a 10% overage. Floor coatings stay thin deliberately — a thicker coat wastes material without adding meaningful durability, since floor epoxy relies more on the substrate prep than on coating thickness.
Common misconceptions
"Any epoxy resin works for any pour depth, I just need to buy enough of it." Depth determines the product, not just the quantity. Standard tabletop epoxy poured too thick can overheat during its exothermic cure and crack, yellow, or cloud. Deep pours need a deep-pour formulation engineered to cure slower and cooler, regardless of how much you buy.
"Epoxy resin and hardener mix 1:1 by volume for every brand." Mix ratios vary by product. Some brands use a 1:1 ratio, others 2:1 or 3:1 by volume or weight. Using the wrong ratio results in a soft, tacky, or improperly cured surface — always check the specific product's technical data sheet before mixing.
Related calculators
Frequently asked questions
How do I calculate how much epoxy resin I need?
Multiply the surface area by the pour depth to get the volume, then convert to fluid ounces: 1 cubic inch equals about 0.554 fluid ounces. A 24×36 in tabletop poured 1/8 inch deep: 864 in² × 0.125 in = 108 in³ × 0.554 ≈ 60 fl oz.
What is the maximum pour depth for epoxy resin?
Standard "table top" epoxy is usually limited to about 1/8 to 1/4 inch per pour to avoid excess heat buildup during curing, which can cause cracking, yellowing, or clouding. Deep-pour epoxy formulations, designed for thick single pours, can go up to 1-2 inches or more in one layer — check your specific product's rated maximum depth.
Do I need multiple pours for a thick coating?
Yes, if using standard tabletop epoxy for a thick pour. Multiple thin layers, each allowed to cure before the next, avoid the heat and shrinkage problems of one deep pour. Deep-pour epoxy is formulated specifically to avoid this and can often go in one pour.
How much extra epoxy should I buy?
A common practice is buying 10-15% extra to account for mixing loss (resin left in cups and mixing sticks), uneven surfaces, and drips over the edge. This calculator applies a default 10% overage, which you can adjust.
Sources & references
This tool uses standard formulas and reference values from:
- • American Concrete Institute — ACI 318, Building Code Requirements for Structural Concrete. concrete.org
- • ICC — International Residential Code (IRC), span, footing and framing tables. codes.iccsafe.org
- • APA – The Engineered Wood Association, allowable span and load guidance.
Estimates for planning only. Span, load and code values vary by jurisdiction — verify against your local adopted code and a licensed engineer before building.