Lye Soap Calculator With Formulation Guide

Select your chosen oils, along with the weight or percentage. The soap calculator will then show the total weight of lye and water required. The result can be instantly adjusted by changing your preferred superfatting level or water/lye ratio. See below for instructions and formulation guides.

Calculator Instructions

Soap Making Guides

Formulating Soap Guide

Calculator Instructions

1. Input a name for your recipe.
2. Choose either Solid or Liquid Soap (see how-to guides below).
3. Choose your Preferred Units Of Measure. I highly recommend grams for more accuracy. If selecting percentage you must input your Total Ingredients Weight in the field that opens up.
4. Select each of your ingredients along with its weight. If you chose to use percentage in the previous step, input a percentage for each ingredient, making sure the total ingredients add up to 100%. The Total Ingredients Weight and Total Lye Before Superfatting will then be calculated and shown below.
5. I always recommend to superfat at 5% as standard, so the default is set to 5%. However, you can increase this up to 10% or decrease it to 0% (see guides below). 
6. I usually recommend selecting a Water Ratio of 2/1, that’s a pretty good standard for any hard soap. For liquid soap, you would want 3/1 (see how-to guides below).
7. Once ingredients have been set correctly, Total Lye Required and Total Water Required will be shown below.
8. Use the Send To Email button to get the recipe sent to you by email (no spam privacy policy).

Important Notes

• SavvyHomemade is providing this lye soap calculator free of charge and is not responsible for any injuries, losses or other damages that may result from using the information provided herein. https://www.savvyhomemade.com/soap-calculator/​
• BETA: The calculator is in beta test, so please do not rely solely on its output to create your soap. Take all necessary precautions when working with Lye and always test your soap with a PH strip before use. Learn how to make cold process soap here, or how to make liquid soap here.
• The lye calculator assumes a 97% purity for NaOH (Sodium Hydroxide) and a 90% purity for KOH (Potassium Hydroxide), these are most commonly sold by most suppliers.
• The sap values you see in the calculator, are taken as an average of saponification values provided by Certified Lye and many other trusted sources. But please remember that depending on a variety of factors, saponification values of oils can change.
• Please send me any feedback, bugs, or errors using the contact form here https://www.savvyhomemade.com/contact-us/

Soap Making Guides

If you’re a complete beginner or you haven’t made cold process, hot process or liquid soaps before, I strongly recommend you follow a tutorial/pre-formulated recipe before formulating your own soap recipe using this lye calculator.

For Making Solid Soap 

Take a look at cold process soap making for beginners. It seems complicated at first, but it’s actually very easy. This is a great resource for anyone looking to pick up this wonderful hobby!

For Making Hot Process Soap

Also known as crockpot soap, a great example is this deliciously sweet hot process soap recipe with orange. You might actually prefer this method!

For Making Liquid Soap

Follow my tutorial on how to make liquid soap at home, I’m now the proud owner of 20 colorful bottles of lush smelling totally natural homemade liquid soap.

Formulating Soaps Guide

If you’ve come to the Savvy Homemade soap calculator and haven’t used it before, you may be wondering what all the fuss is about. Perhaps you’ve followed a few of my tutorials, or others across the web.

But have you ever asked yourself, can I come up with my own soap recipe? The answer is, absolutely! And this guide will talk about some of the more important aspects of choosing a recipe using the lye calculator.

Oils, Butter & Waxes, Oh My!

Besides the water and lye, your recipe will be comprised mostly of carrier oils, butters and occasionally some waxes.

While there are other ingredients we will talk about later, these are the bulk of your recipe and it’s important to get them right!

When you’re choosing oils, butters and waxes for your soap, you have a lot of freedom. Liquid oil is the only thing that you absolutely need. In fact, you can make soap with just olive oil! The butters and waxes are optional but definitely worth considering as they can add some wonderful properties to your soaps.

As a basic ratio, I like to recommend 50% liquid oil, 25% solid oil (something like coconut) and 25% cosmetic butter. This should give you a lovely soap that is medium-soft and rich with nourishing qualities. If you want to use a wax, exchange it with 5% of the butter (so 50% liquid oil, 25% solid oil, 20% cosmetic butter and 5% wax). Keep in mind that all butters and wax have different densities, so this basic formula may have to change depending on the type you use.

For instance, if you want to use a wax like beeswax in your soap but you’re vegan, you can exchange it for candelilla wax. However, candelilla wax has double to the stiffness of beeswax, and so you may want to use 2.5% instead of 5% in order to achieve a similar texture to your soap. There’s a similar story for shea butter and cocoa butter, cocoa is harder and will change the texture when substituted (although both are 100% vegan in this case).

Nevertheless, these ratios can totally be stretched, played and experimented with using the lye calculator. You could end up with a new breakthrough formula in soap making, or perhaps your next flop. Keep in mind that cosmetic butters and waxes (waxes especially) can speed up trace considerably. If using high butter or wax ratios, consider using oils that don’t trace very quickly to slow down the chemical reaction.

Soap making is all about experimenting

Sometimes you will formulate a soap and it just doesn’t turn out the way you were hoping. Try to remember that this isn’t necessarily a bad thing. When you make a mistake or things go wrong, you’re learning valuable lessons about what will and won’t work.

Just start off simple, using readily available and affordable oils, butters and waxes and always use the calculator in order to figure out how much water and lye to use. That way, it really shouldn’t matter if things don’t necessarily go to plan. Even the very best soap makers make mistakes sometimes, just keep yourself motivated and you’ll be a master in no time!

Fatty Acids, What Are They Good For, Cleansing, Conditioning, Lather?

All carrier oils, butters and waxes have what we call ‘fatty acids‘. Without going into too much unnecessary detail, these substances are what lend wonderful and useful properties to our soaps! Let’s take a look at a breakdown of the most commonly found fatty acids in our soap making ingredients and how they affect our soap.

Each oil, butter or wax contains differing amounts of these fatty acids. Many contain a few of them, but not all of them.

Considering the fatty acid breakdown of each individual soap making ingredient is an important aspect of formulating a soap. Nevertheless, individual oils, butters and waxes can bring further benefits, and so try not to focus solely on fatty acids.

Most Commonly Used Oils, Fats & Butters With Properties & Sap Values

Let’s take a look at a breakdown of the most commonly used oils, butters and waxes for soap making, including their individual benefits, fatty acid content and any specific considerations and information regarding ratios (if applicable).

If you’re using our lye calculator, you don’t need to worry too much about the SAP values as the calculator will handle that. However, I have listed them for educational purposes.

Superfatting With the Lye Calculator

So here’s the deal with superfatting. When you make soap at home, the majority of the oils saponify (turn to soap). However, superfatting allows you to add extra oil that won’t saponify, leaving you with a soap that has luxurious oils left over to nourish your skin.

I always recommend to superfat at 5% as standard, so when you use the Savvyhomemade lye calculator for soap making you will see that the default is set to 5%. However, you can increase this up to 10% or decrease it to 0% by using the superfatting level slider. For a super luxurious soap, you may wish to have a relatively high superfat content. However, a teenager with acne wouldn’t benefit from superfatting over 3%. So when deciding how much to superfat, always keep the purpose of the soap at the forefront of your mind.

If you want to superfat with the bulk oils of your recipe, my soap making calculator will handle that for you when you use the superfatting slider. This is great, because it is easy to do and quite effective. Nevertheless, you will not be able to guarantee which oils in your recipe will be superfatted, or your superfatting will be split across your oils equally.

Making Use Of Precious Oils When Superfatting

However, there are times when you might want to make use of precious oils for superfatting, which may require you to be more precise. Argan oil is an excellent example of this. Because argan is so damn expensive, using it in the bulk of your soap will make it extremely expensive to reproduce. This is especially problematic for anyone who plans to sell their soap.

While you can add argan oil to the calculator, you will have the problem of all of your oils being superfatted as opposed to just your argan oil. If you want it more precise, we’ll need to use a little math. Don’t worry, it’s nothing you can’t do on a calculator.

So, if you want to superfat with something like argan oil, use the calculator as you normally would, but leave out the argan and make sure the lye calculators superfatting slider is set at 0%. Then, you are free to add up to 10% of your argan oil by adding it at trace with your aromas, colors and added botanicals. Though I would recommend 5%.

The Formula

If you’re not sure how much 5% of your total batch is, there’s a simple formula you can follow. Take the total weight of your soap batch, divide that by 100 and then times that number by 5 (or whatever percentage you wish to superfat). That should give you the amount of argan oil you’d need to use.

So, for example, if my batch is 1.3kg and I wanted to superfat with argan oil at 5%, I would follow this calculation: 1300/100*5 = 65g. I would then add 65g of argan oil at trace, along with my extra ingredients. While some of this may still saponify, it is much more likely to remain as a superfat when you add it at trace, as opposed to with the bulk of your oils in the emulsion stage.

Saponification Values

The sap values you see in the chart above, of which are the same used by the calculator, are taken as an average of saponification values provided by Certified Lye and many other trusted sources. But please remember that depending on a variety of factors, saponification values of oils can change.

For example, sap values may change depending on the supplier, manufacturer, region of origin and even time of year. However, this should not affect you when using this calculator, as the differences will only be small and margin for error is minimal.

If you would like to check the sap value we have applied to a specific oil, select it and set the weight to 1. As an example, if we choose almond oil and set the weight to 1 gram, it will show the sap value is 0.137

Water/Lye Ratios With the Soap Calculator

The amount of lye and water you’ll need to properly saponify your oils, butters and waxes into soap will be handled by the calculator. So, no need to get your calculator out for this one!

I usually recommend selecting a ratio of 2/1 in the water/lye section of the calculator. That’s a pretty good standard for any hard soap. For liquid soap, you would want 3/1.

You’ll notice I have offered the option to lower the ratio in the calculator. This is there for experienced soap makers who want to try and speed up saponification.

Sometimes certain soaps can take a very long time to harden in the mold (e.g. when making castile soap I use 1.5/1). By lowering the amount of water, you can get that soap out and start curing it earlier. Nevertheless, this does leave more room for error. I would only recommend utilizing this option if you’re experienced with making soap.

Other Ingredients Worth Thinking About

Before considering adding any extra ingredients, keep in mind that all of the below will accelerate trace, some quicker than others. Just be sure to add these at a light trace, right before you plan to pour into the mold.

Essential and Fragrance Oils

We all want a nice smelling soap, this is where essential and fragrance oils come in! Let’s talk about them separately, though, because both have their strengths and weaknesses.

Essential oils

are amazing in soaps. They smell wonderful but also have many benefits that can be imbued in your soaps. They’re also 100% natural, and so great for anyone who wants to avoid synthetic chemicals. To learn more about these benefits and where to buy them, take a look at our essential oil use guides.

However, essential oils can hurt your wallet. Because they’re a natural product, supply is not always assured. This, in conjunction with the process in which they’re extracted, they can be very expensive and their price can vary from year to year.

Furthermore, various factors (such as climate) can change how essential oils smell. For instance, if the region that grows the lavender used for your essential oil has less rainfall one year, this could impact the quality of the essential oil. So there are a variety of issues regarding essential oils that you should keep in mind, especially when it comes to producing a consistent product.

Fragrance oils

Now, let’s chat about fragrance oil. These aromatic, albeit synthetic oils are the unnatural cousins of the essential oil. They’re cheaper, more consistent and the supply is always available. They also come in waaaaaay more varieties than essential oils do. Want a soap that smells like blueberry muffins? Fragrance oils are the way to go.

But, there’s a big catch. Because they’re synthetic, they have literally no benefit other than that they smell nice. They’re also packed full of artificially produced chemicals made in laboratories. I don’t know about you, but I don’t like the idea of smearing my body with something so unnatural. While the long term research on the safety of fragrance oils doesn’t currently exist, I just personally wouldn’t chance it.

There’s also something worth mentioning, and that’s how fragrance oils behave in soap. I find fragrance oils to be the bane of my soapmaking life. I can’t tell you the number of times I’ve had soap rice after adding them at trace. While you can buy fragrance oils that are formulated for cp and hp soap making, even those seem to be a bit hit and miss sometimes. Fragrance oils are great for melt and pour soap, but just don’t seem to be great for cp and hp soap.

Colorants

Dying your soaps can be a great way to make them more beautiful and eye-catching. Like essential oils and fragrance oils, you have two options here; natural and unnatural.

For the natural, there are a few options you can go for. Tarragon, for instance, is a great way to get a nice orange looking soap without impacting the scent profile of your soaps. There are other options, though, so take a look at my soap colorant section of my soap supplies page. The only problem is that you are more limited in what you can do and what colors you can get out of natural dyes. They’re also not all that vibrant, either.

As for unnatural, you have the micas. While mica is technically a naturally occurring mineral, many of the micas you find on the market are adulterated with synthetic pigments to get them to look nice and bright. While you’ll see many suppliers claiming their micas to be all-natural, I’m not sure I always trust them on that one.

Nevertheless, I have used micas many many times and haven’t have a problem. They are beautifully bright, vivid and come in a plenitude of colors, shades and hues. I tend not to use a lot of mica in my soaps anyway, so I think a pinch of something not so natural probably won’t hurt. Whereas dumping a load of synthetic fragrance oil is, for me, a big no-no.

Be careful when using anything that claims to be a liquid soap dye in your cp and hp soap. These are usually formulated for melt and pour soaps and not for cp or hp methods. Always make sure the product say it is suitable for cp and hp, otherwise pass on it.

Added Extras

Now for the little extras that aren’t necessary, but could make your product that bit more interesting or useful.

First, let’s talk about added botanicals. Often I’ll add dried or crushed organic herbs into my soap. A good example of that is my lavender and mint recipe, where I use crushed dried mint leaves. These add a great ascetic to your product and also scream ‘I am natural’ to your customers (if you sell your soaps, that is).

Be careful what you choose, though. dried flowers, for instance, are great when sprinkled on top but completely lose their color when stirred into the batter. Just be mindful and do your research.

Other added extras include exfoliants. Adding something like poppy seeds, jojoba beads or crushed almond shells can give your product an added exfoliating benefit. You’ll be able to clean your skin but also get rid of dead skin cells at the same time! I love doing this, and the pieces of exfoliants can look great in your soaps, too!

Functional Additives

Lastly, we have functional additives. Sometimes you’ll want to add an extra ingredient that does something specific. Lactic acid, for instance, jumps to mind immediately. This ingredient will make your soap harden up much more quickly. Its something I have worked with in the past, but I personally prefer to formulate a recipe that works great on its own.

Another optional ingredient you could try is titanium dioxide. This product will help lighten your soap. An all-natural soap has a tendency to look a little beige or dull. By adding this, you can actually get a soap that looks very white and pure. Nevertheless, it is entirely unnatural and I ordinarily will not make use of it.

This list of functional ingredients to use in my soap calculator will likely get longer as I discover new ones, so come back from time to time and check out what I’ve discovered!

All Homemade Soap Recipes

Your Help

Please send me any feedback you have for the calculator, including any bugs or errors, using the comments below or the contact form here https://www.savvyhomemade.com/contact-us/. Going forward this will help me improve and perfect the app for everyone.

Thanks
Angela