SoapCalc is a great resource for making soap but it takes some work to navigate, especially the first few times you use it.
The main calculator used for soap recipes is located here — http://soapcalc.net/calc/SoapCalcWP.asp.
The tool is free to use and DOES NOT require you to download anything or sign up for anything with a credit card. When you first land on the page, you may encounter lots of big green “Download” buttons. Those are all ads that you can close out or minimize…you don’t need to download or enter any personal details into SoapCalc to use it.
Moving in order through the numbered sections, for #1 you’ll typically select NaOH, which is the default choice. NaOH = Sodium hydroxide = lye.
For weight of oils in #2, I recommend that you change pounds to ounces (although some soap makers work in grams). Keep in mind that this is weight of the oils only, and not the total weight of your oils + water + lye + fragrance oils.
It’s difficult when first starting to know the starting weight to enter here as this will vary based on the size and shape of your mold. For a 1 lb silicon mold, you’ll typically have 14-15 ounces of oils in your recipe. A 3 lb mold will call for about 33-34 ounces of oils and a 5 lb mold needs around 55-56 ounces.
You may need to undertake some trial and error and adjust (if you have leftover batter, reduce the amount of oils you’re entering; if you don’t have enough, increase the amount) to get the right amount for your mold.
For #3, select the bottom option “Water: Lye Ratio” and enter “2:1” in that box. This will have you starting with a standard 2:1 ratio.
For #4, leave these with the default entries. You may adjust these over time for various recipes but the defaults are good starting points.
In section #5, you’ll see many items listed under “Oils, Fats, and Waxes”. If you click on one, you’ll see the properties of that oil to the left under “Hardness”, “Cleansing”, etc.
Select an oil you’d like to add to your recipe, then click the “add” button under section #6. You’ll see your oil name appear in section 6 now.
Add each oil that you’d like in your recipe. Order doesn’t matter. If you need to remove one, enter the number of the line its on next to the “Remove #: button, then click the button.
Once you’ve added your oils that you’d like to use, you need to add percentages for each. This takes some playing around and experimentation, but a good starting point for beginners would be 50% olive oil, 20% coconut oil, 10% castor oil, and then the remaining 20% of oils whatever you’d like to try or have on hand.
Once you have your oil percentages entered, click “Calculate Recipe” in section #7. Some numbers will pop up on the screen.
Now click “View or Print Recipe” and your soap recipe will pop up in a new window.
Under the colored section for “Water”, “Lye”, “Oils” and “Fragrances” you’ll see listed the suggested amounts to add of each oil, shown in pounds, ounces, and grams.
At the bottom under “Soap Bar Quality”, you’ll see how your recipe measures up to the recommended ranges. Don’t worry if you’re not within the ranges as these are guidelines and not hard rules.
If you want to tweak your recipe, go back to the first window and simply make changes, then click “”Calculate Recipe” and then “View or Print Recipe”. That will now display the new tweaked recipe.
At the bottom is a print page function and you can also copy/paste it out into a Word doc or Excel.
While it’s a lot of steps, it gets easier with practice and most steps are straightforward. The trickiest part is knowing the weight of oils to enter in #2 when starting with a brand new recipe (and not adjusting an existing one) but a little trial-and-error will get you there.