How Our Epoxy Calculations Work

For a rectangle, volume = length × width × depth. For a circular pour or cylinder, volume = π × (diameter / 2)² × depth. For a sphere, volume = 4π × (diameter / 2)³ / 3. All dimensions must use the same unit; the result is cubic inches for inch inputs or cubic centimeters for centimeter inputs. Hollow spaces, inserts, sloping bottoms and irregular channels need their own measured volumes rather than a bounding box.

Raw volume is the geometric minimum. For the general calculator, order quantity = raw volume × (1 + waste percentage / 100). Its default 8% is an editable planning allowance, not a measured industry average or manufacturer requirement. The conservative scenario adds another eight percentage points. Record your actual cup loss, leaks and edge runoff to choose a buffer for later projects.

Always verify maximum pour depth, cure windows, mix ratio, and coverage claims against the product documentation you plan to buy. This site is a planning tool, not a replacement for the manufacturer data sheet.

• 1 US gallon = 231 cubic inches; 1 US fluid ounce = 231 / 128 = 1.8046875 cubic inches. These are US liquid units, not Imperial gallons or weight ounces.
• 1 inch = 2.54 cm; 1 liter = 1,000 cm³, or approximately 61.023744 cubic inches. Volume in liters = volume in cm³ / 1,000.
• A 48 × 18 × 1.25 in cavity holds 1,080 in³. Divide by 231 to get 4.6753 US gal. Multiplying by 1.08 gives 5.0494 gal (19.114 L) to plan for, displayed as 5.05 gal.
• At an illustrative $95 per mixed gallon, that order costs about $479.69 before kit rounding, tax or shipping. The calculator rounds the displayed dollar estimate.

• For a surface measured in square feet, raw volume in in³ = area × 144 × thickness in inches. One US gallon at 1/8 in covers 231 / (144 × 0.125) = 12.833 sq ft before edges and waste.
• The river calculator divides the length into equal segments and adds segment length × segment width × depth. Width entries represent each segment's average. For unequal segment lengths or changing depths, calculate the sections separately.
• The river model adds waste, an optional 8% seepage allowance and an optional 5% seal-coat allowance to the same raw volume. With 12% waste and both options selected, the factor is 1.25, not 1.12 × 1.08 × 1.05.
• Coverage and surface-coat models also include edge/runoff allowances. Check the result breakdown to see each contribution; use one appropriate model rather than adding the same allowance twice.

• For a confirmed manufacturer's A:B volume ratio a:b, Part A = mixed volume × a/(a+b), and Part B = mixed volume × b/(a+b). Unknown ratios remain unconfirmed. Weight ratios require the product's weight instructions and are not inferred from geometric volume.
• The deep-pour calculator estimates layers as ceiling(total depth / selected maximum layer depth). A 2.5 in fill at a 1 in maximum needs three layers. Actual timing, batch size and surface prep come from the product sheet.
• River/general layer guidance is a planning prompt, not a tested product limit. Use the deep-pour tool with the exact manufacturer's limit before deciding a pour schedule.
• Quantity-based cost = recommended mixed quantity × the entered unit price. The floor-cost model uses floor area × selected coating rate, plus specified repairs, moisture barrier or resurfacing, and a contractor minimum where applicable. U.S. floor prices have sources and dates on the floor-cost page; they are estimates, not quotations.

You can reproduce the examples above with a hand calculation and compare imperial and metric inputs for the same shape. Published product limits are linked from the relevant guides. No claim is made that default buffers were established through a field trial: they are adjustable assumptions. Rounding, kit sizes, hidden voids, substrate absorption and installation conditions can change what you need to buy. Report a mismatch with the page URL, units and input values through Contact.

The area/thickness model uses wet mixed volume: m² × mm = L. The label model uses area × coats ÷ the selected product's coverage per mixed gallon or liter. Edge and waste percentages are added to raw volume as separate percentage points. Count multiplies the per-piece quantity. Whole kits are rounded up from required mixed volume divided by the kit's stated total mixed yield. A matched kit purchase is not an instruction to mix the whole kit at once.

No mix ratio is inferred from a shape or resin category. A user-entered volume ratio a:b splits the mixed volume as a/(a+b) and b/(a+b). Weight ratios need the manufacturer's weight quantities or component data and are not computed from volume alone. Maximum layer depth and maximum mixed batch volume are separate user-entered limits. Unknown limits remain unknown; this tool does not establish a safe casting schedule.

• Crosslink Technology: volume and weight mixing ratios
• MAS Deep Pour: technical bulletin and product conditions

Direct cost = resin + supplies + packaging + labor hours × hourly rate + overhead. Expected cost per successful piece = direct cost ÷ (1 − failure rate). Selling price = (expected cost + fixed selling fee) ÷ (1 − percentage selling fee − target profit margin). Margin refers to profit divided by selling price. Shipping, tax and other costs are included only when entered. Fees plus margin must stay below 100%.

Added finite-number and percentage checks, mL display for small quantities, piece counts, direct surface area, product-label coverage, explicit product ratios and limits, whole-kit rounding and a complete resin-art selling-price model. Same-task shape and language quantity entries were consolidated. These changes concern the software and worked examples; they do not claim laboratory or installation experience.