Water Displacement & Irregular Shape Calculator
For irregular master models (clays, pinecones, 3D prints) that defy geometric measurements. Submerge, weigh the displaced water, and obtain exact material mix recipes instantly.
Water Displacement Calculator
How to measure displacement:
- Fill a container completely to the brim with water and place it inside a larger tray.
- Submerge your master model completely in the water.
- Weigh the water that overflows into the tray. Enter that weight below.
Displacement Results
Archimedes' Principle & Craft Mold Calibrations
When casting custom molds of organic objects, standard geometric calculators fail. Natural items like pinecones, tree bark, handmade clay figures, and detailed 3D prints have complex, irregular surface areas. Attempting to estimate their volume using rectangular or cylindrical bounds leads to severe over-pouring or under-pouring of expensive materials.
The solution lies in **Archimedes' Principle of buoyancy and fluid displacement**. This law states that any object, wholly or partially submerged in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object. More practically for makers, the physical volume of a fully submerged object is exactly equal to the volume of the water it displaces:
1 gram of pure water = 1 cubic centimeter (cm³) = 1 milliliter (ml)
By placing your master model into a container filled to the absolute brim with water and measuring the weight of the overflow water in grams, you obtain its net volume in milliliters.
Adjusting for Specific Gravity (Material Density)
While the volume of the overflow water directly gives you the volume of your model in milliliters, you cannot pour the same weight of resin or silicone. You must scale the volume by the material's specific gravity:
- Liquid Silicone: Specific gravity is usually between 1.18 and 1.34 g/ml. A mold that displaces 100 grams of water requires approximately 118 to 134 grams of silicone.
- Epoxy Resin: Specific gravity averages 1.10 to 1.15 g/ml.
- Jesmonite AC100: Density is exceptionally high, sitting at 1.75 g/ml. 100 ml of volume requires 175 grams of mixed composite.
Select your target material in the dropdown above, and our engine automatically applies the correct density factor and splits the totals into Part A and Part B weights.