Precision ratios for makers & handmade sellers.
Stop wasting expensive materials and guessing your margins. MakerRatio provides precise, workshop-grade material formulas and profit estimation for resin casting, candle pouring, silicone molds, and craft businesses.
Craft Estimation Tools
Select your material workflow to open the interactive ratio visualizer, preset density options, and Etsy landed cost sheets.
Resin Mold Calculator
Calculate the exact Part A and Part B weights for standard and custom shapes (Rectangle, Sphere, Hexagon, Dome). Built-in presets for ArtResin, TotalBoat, Let's Resin.
Candle & Wax Melt Calculator
Determine wax weight flakes and fragrance oil loads (6%–12%) for glass containers or custom silicone molds.
Epoxy Countertop Calculator
Calculate volumes for seal coats, flood coats, or deep river channel pours. Get recommended gallon kit purchases.
Silicone Mold Calculator
Calculate the amount of 2-part liquid silicone rubber (Part A/B by weight or volume) required to pour custom mold boxes. Supports displacement calculations for complex items.
Jesmonite & Plaster
Calculate the 2.5:1 weight split (Base Powder to Liquid Resin) for Jesmonite AC100 castings.
Concrete Planter
Calculate standard concrete mixes and lightweight Hypertufa planter weights using outer/inner wall dimensions.
Water Displacement
Measure volume and mix ratios for irregular master models (3D prints, clays) using Archimedes' water overflow weights.
3D STL Volume Calculator
Upload your `.STL` 3D printing mesh files to automatically analyze physical bounding box volume (ml / cm³) completely client-side. Get instant resin and silicone splits.
Universal Custom Ratio Tool
Fully customizable mix parameters. Toggle weight vs volume ratios (like 100:43 or 2.5:1) and target specific gravity parameters.
Terrazzo Chips Calculator
Calculate the exact weights of terrazzo stone chips, acrylic flakes, or glass shards and your composite casting base (epoxy, Jesmonite, cement).
Etsy Fee & Profit Margin Calculator
Calculate your actual material landed costs (with shipping & tariffs), add hourly labor rates, and estimate optimal retail listing prices that cover all Etsy fees.
Candle Wick Size Selector
Match jar diameters and wax types to exact ECO, CD, HTP, and wooden wicks. Includes double-wicking rules and FO wick-up math.
Epoxy Cure vs. Temp
Calculate working pot life, demold times, and full cure schedules across 10 brand formulations with thermal runaway alerts.
Jesmonite Pigment Drops
Compute exact drops and grams for pastel, medium, and saturated hues in AC100/AC300 without structural crumbling.
Craft Batch Cost & Keystone Pricing Calculator
Calculate true unit COGS across raw materials, packaging, and hourly labor wages. Model Keystone wholesale (2x) and retail (4x) pricing with exact Etsy and Shopify fee deductions.
Clay Shrinkage & Lid Fit Calculator
Calculate exact wet wheel-throwing dimensions to hit fired target sizes, or project fired results across commercial clay bodies (Laguna B-Mix, Speckled Buff, Porcelain). Includes lid & gallery caliper matcher with glaze clearance tolerances.
Why Accurate Material Density Matters
Crafting is, at its heart, the science of ratios. A single mismatch in material density can cause resin to remain sticky, candles to sink, or concrete planters to crack. Many online calculators assume a uniform specific gravity of 1.0 (water equivalent), which leads to incorrect weight calculations. MakerRatio addresses this gap by utilizing a specific gravity database tailored to commercial hobby brands.
Mathematical Formula Transparency
Every volume calculation normalizes physical units (inches, feet, yards) to centimeters to ensure that 1 cubic centimeter equals 1 milliliter. Weights are then computed by multiplying the volume by the material's specific density:
For composite materials, the resulting total weight is partitioned precisely. For example, Jesmonite AC100 uses a 2.5:1 ratio, meaning liquid resin is calculated as Total Weight / 3.5, and base powder as Liquid Weight × 2.5.
Frequently Asked Questions
How do I calculate raw materials needed for resin, silicone, or candle molds?
To calculate the raw material weight required for any mold casting, you must determine the geometric volume of your mold (in cubic centimeters or milliliters) based on its shape (e.g. cylinder, rectangle, sphere). Then, multiply this volume by the specific density (specific gravity) of your material (typically 1.13 g/ml for epoxy, 1.34 g/ml for silicone, or 0.86 g/ml for soy wax). Adding a 5% to 10% safety waste factor is recommended to compensate for meniscus curvature and container residue.
Why does generic water-based volume calculation fail for crafts?
Water has a specific density of exactly 1.0 g/ml. However, hobbyist materials are either denser or lighter than water. For example, epoxy casting resins are about 13% heavier than water (1.13 g/ml), and silicone is up to 34% heavier (1.34 g/ml). Conversely, soy wax is 14% lighter than water (0.86 g/ml). Using water volume directly without specific gravity adjustments leads to under-filled molds or wasted material.
What is the correct way to calculate fragrance oil weight for candles?
In professional candle making, fragrance load (e.g., 6% to 10%) is calculated relative to the weight of the wax alone, not the total target weight of the candle. To calculate wax weight, divide the total target weight by (1 + fragrance load percentage/100). The fragrance oil weight is then calculated by multiplying the wax weight by the fragrance load percentage. This prevents overloading the wax, which causes fragrance oil to pool on the candle surface (sweating).
How do I determine the profit margin for my Etsy or handmade crafts?
Calculate your Total Production Cost by adding your Landed Material Cost, labor cost (hourly wage multiplied by production hours), and packaging costs. Subtract this total along with Etsy's transaction fee (6.5%), payment processing fee (3% + $0.25), and listing fee ($0.20) from your retail selling price to find your net profit and margin.