My 3 Favorite Saponification Calculators

When you start making cold-process soap, one of the first things that can be a bit intimidating is calculating the sodium hydroxide (lye).

You quickly discover that you can't just take a recipe and replace one oil with another. Every oil requires a different amount of lye. Therefore, you have to use a saponification calculator to determine the amount of lye and water needed for your recipe.

Through my research, I have used several calculators. Today, I would like to introduce you to three of my favorites.

They all basically do the same thing at their core, but they have slightly different approaches.

The first one is very comprehensive and is probably the one you will encounter most often.

The second one is much simpler and particularly interesting when you are just starting out.

And the third one is perfect when you start wanting to go a bit deeper into analyzing your recipes.

1. SoapCalc: The Ultimate Classic

https://soapcalc.net/calculator 

If you have ever looked for a soap calculator on the internet, you have probably already stumbled upon SoapCalc.

It is a very well-known tool in the artisan soapmaking world. At first glance, its interface can look a bit busy, especially when you are a beginner.

But don't let that discourage you!

Once you understand where to input your oils and which parameters to look at, it becomes genuinely practical.

What I like about SoapCalc

The first thing I appreciate is that it makes it easy to build a recipe using multiple oils and butters.

You choose your oils, indicate their quantities or percentages, and the calculator gives you the required amount of lye.

But it doesn't stop there.

It also gives you several pieces of information about the recipe, such as its hardness, cleansing power, conditioning, and various aspects of its lather.

This is very interesting because it helps you understand that every oil plays a different role in your soap.

For example, if you increase the coconut oil, you aren't just making "more soap with coconut oil." You are also modifying certain characteristics of the recipe.

And this is where calculators become truly interesting: they allow us to see how our choices influence our formulation.

My favorite little bonus: The PDF

Another feature I really like is the ability to easily save your recipe as a printable document.

This is very handy if you like keeping your recipes in a binder or if you want to keep a copy of every test batch.

Personally, I find this particularly useful when you start modifying your recipes and making multiple trials.

Who is it for?

I would say SoapCalc is perfect for someone who wants a fairly comprehensive tool that they can keep using as they progress. In the beginning, you can simply use it to calculate your lye.

Then, over time, you can start looking at all the other information it provides.

2. TheSage Lye Calculator: Perfect for Understanding the Basics

https://www.the-sage.com/lyecalc/

The second calculator is the one I find particularly interesting for beginners.

Why?

Because it is much simpler.

When you discover saponification, you can easily find yourself staring at a calculator filled with numbers and asking yourself: "Wait, what am I supposed to look at here?"

With TheSage, you get that feeling much less.

A great tool for understanding superfatting

One thing I particularly like is the ability to see how the amount of lye changes depending on the chosen superfat percentage. This lets you see very concretely what is happening.

And if you are a beginner, it's an excellent way to understand that superfatting isn't just a random number you pick. The more you increase the superfat, the more you reduce the amount of lye used.

It also helps you better understand water

The calculator also allows you to work on the concentration of the lye solution.

This can be very useful when you start learning the difference between:

"How much water should I use?"

and

"What lye concentration do I want?"

These are two related, but different, ways of thinking about the amount of water used in a recipe.

For a beginner, I find this particularly educational.

You can modify the parameters and observe what changes, rather than just entering a recipe and accepting the result without truly understanding what is going on.

Who is it for?

I would particularly recommend TheSage to someone who is just starting to learn formulation and wants to understand the calculations before diving into more complex recipes.

It might not be the one I would use to analyze a recipe down to its tiniest details, but for learning the basics, it is very interesting.

3. Mendrulandia: When You Want to Go a Bit Further

https://calc.mendrulandia.es/

And finally, there is Mendrulandia.

At first glance, it looks a lot like SoapCalc: you choose your oils, you enter the quantities, and the calculator helps you build your recipe.

However, it also provides a lot of extra information.

This is what makes it particularly interesting once you start getting more comfortable with formulation.

Why do I like this tool?

In the beginning, you simply want to know:

"How much lye do I need to use?"

Then, after a few recipes, your curiosity generally starts taking over.

You start wondering:

"Why is my recipe harder than the previous one?"

"Why does this one lather more?"

"What happens if I replace part of my coconut oil with shea butter?"

"Is this new recipe balanced?"

This is the moment when a tool like Mendrulandia becomes very interesting.

It allows you to look at your recipe with more detail and start comparing formulations.

And if you like experimenting, this is the exact kind of tool that might make you want to spend even more time playing with your recipes!

Who is it for?

I would rather recommend it to someone who already knows the basics of saponification and is starting to want to understand what goes on behind the numbers.

You absolutely do not need to start with this one.

But when you feel like going further, it is definitely worth discovering.

So, Which One Should You Choose?

The good news is that you don't need to choose just one.

I even find it interesting to know all three, as they can serve different purposes.

• SoapCalc

• My choice for: Building and easily saving your recipes.

• It is comprehensive, very well-known, and provides a lot of information.

• TheSage

• My choice for: Learning.

• Its simple interface makes it easier to understand the relationship between the amount of lye, the superfat, and the water.

• Mendrulandia

• My choice for: Going deeper.

• It is particularly interesting when you start analyzing your recipes and experimenting further.

And above all: don't let the numbers intimidate you!

When you start making soap, calculators can look complicated.

You see percentages, grams, SAP values, concentrations, superfats... This can give the impression that you need to be great at math to make soap.

That is not the case.

The important thing is mainly to gradually understand what each piece of information means.

In the beginning, you can simply learn to:

1. choose your oils;

2. enter their quantities into the calculator;

3. choose your superfat percentage;

4. determine your concentration or water amount;

5. check the calculated lye amount;

6. and then double-check your recipe before making it.

Over time, the numbers become much less intimidating.

And above all, you will start to understand why your calculator is giving you those numbers.

In my opinion, that is the real goal.

A saponification calculator shouldn't just be a black box you ask, "Give me the amount of lye."

It can also become a true learning tool that helps you understand how your oils, your superfat, and your water amount will influence your recipe.

And that is precisely where soap formulation becomes truly exciting.