This is a Javascript-only soap calculator able to be deployed as a single html file and works fine offline when downloaded locally as no web requests are made.
Other reasons why I made this over the existing calculators are:
For a live version of this see: https://malkiewiczm.github.io/soap/
For the source code see: https://github.com/malkiewiczm/soap_lye_calculator
Q: Where are the saponification and fatty acid values derived from?
A: They are taken from www.SoapCalc.net. Based on what I've seen other online calculators take them from too but without credit.
Q: Why is your definition of "super fat" different than "lye discount". Aren't they the same thing?
A: I took "super fat" to mean "use this percent more fat in the recipe" and "lye discount" to mean "use this percent less lye in the recipe". Online most people refer to them as being the same thing, taking on the latter definition but it made more sense to me this way.
Q: Why is there no "water discount" field?
A: Water discount as a percent doesn't make that much sense to me. What is it a percentage of? Online the consensus seems to be it is just a percentage of the default of the calculator. In my opinion, if the intended purpose is to use less water in the recipe then it is better to be explicit and enter a higher lye concetration.
Q: What units are the weights in?
A: The units can be whatever you want to be. Since all the math is relative the units of weight don't matter as long as they are the consistent. If you take a recipe that makes 500g of soap and use it to make 500 lbs of soap all of the numbers are the same.
Q: What do the symbols and colors on the bar graph mean?
A: The dark triangles show where the different oils in your recipe lie on the graph. The hashed lines show where the recipe currently lies. Since the soap recipe is a ratio of oils, the level indicated by the hashes will always be between the triangles and can be thought of as your recipe being "pulled" towards the triangles depending on how much of that oil is present. The background color is lighter where the recommended amount is from www.SoapCalc.net is, but that is just a general guideline.