Calculate the volume of the mold in cubic inches Multiply the volume of the mold by 0.4 to find the total amount of oils in the recipe. Calculate the amount of each individual oil using the percentages in your original recipe. Enter that amount of oils into an online lye calculator to get the final recipe quantities
Prepare the recipe as you normally would using the quantities from the lye calculator, and the soap should come close to perfectly filling the soap mold, whatever its size or shape. Then, using the percentages in your recipe, calculate each of the individual oils. Enter the oils in the online lye calculator to come up with the final recipe sized perfectly for that mold. It’s not as hard as it sounds. The radius is 1/2 of the total width of the tube. For a 3-inch tube, the radius is 1.5 inches. “Squared” is the number multiplied by itself, so 1.5 X 1.5 = 2.25. Pi is a constant generally calculated at 3.14. So, for a 3-inch PVC tube mold that is 6 inches high, the calculation is: 3.14 (Pi) X 1.5 (radius) X 1.5 (radius) X 6 (height) The volume of any cylinder is calculated using Pi X radius X radius X height. The calculation gives you the volume of the container in cubic inches, which you then multiply by 0.4 to get the total amount of oils needed. 3.14 X 1.5 X 1.5 X 6 X .40 = 16.96 ounces of oils. Using the percentages in your recipe, calculate the individual oils. Put the oil totals into the online lye calculator for the final recipe quantities. Fill the mold with water and then pour that water into a measuring cup. Multiply the number of fluid ounces of water by 1.8 to get the total cubic inches of the mold. For example, if your mold holds 12 ounces of water, 12 X 1.8 = 21.6 cubic inches. 21.6 cubic inches in the mold X 0.4 = 8.64 ounces of oils in that recipe. Enter the 8.64 ounces of oils—best to round up to 9 or at least to 8.6—allocated by the percentages of each oil in your recipe, and use the lye calculator to give you the final recipe. Note: This method works because a fluid ounce of water weighs one ounce, which is not the case with other liquids. Soapmaker Software is a complete software program for calculating recipes, resizing for different molds, calculating costs of ingredients and batches of soap.
