6 Lye Calculators for Cold Process Soap

If you're creating your own soap recipes from scratch or even if you're using a recipe from a book, a website, or a trusted fellow soap maker, running your recipe through a lye calculator before getting started is a crucial first step. Using a calculator will help you make sure that your ratios of water, oils, and lye are correct. Having the perfect ingredient ratio will ensure that your batch of soap comes out just right without any unexpected surprises.

In theory, the cold process, which involves mixing set amounts of oils with an alkali (or lye) is easier than heating the ingredients and dropping them into molds. Even though the process is easier, do not skip using a calculator. The following are six of the best soap calculators to help you figure out how much lye to add. Each is easy to use and accurate, so you can trust the results.

  • 01 of 06

    New Soap Calc

    Homemade Lye Soap
    Michael Westhoff / Getty Images

    The folks at Soap Calc are constantly improving and streamlining their online lye calculator. It continues to be one of the best and most comprehensive lye calculators on the internet, offering helpful suggestions and hints that both notice and veteran soapmakers will appreciate.

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    SoapMaker Software

    If you're really serious about soap making and creating your own recipes, you'll want to invest in SoapMaker Software. The Lite version provides everything the hobbyist needs, while the Professional version includes ways to track your inventory and supplies list. It also features a comparison of the costs of various recipes along with other retailer tools. The versions use the same lye calculator, so if cost is an issue, start with the Lite version; you can always upgrade later.

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    Bramble Berry Lye Calculator

    Bramble Berry's calculator is a great simple soap calculator and it has been revised to include liquid soap. With this tool, you can only superfat up to 10 percent. If you come across an issue, the Bellingham, Washington-based company has staff available to answer your questions. 

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    Majestic Mountain Sage Lye Calculator

    One of the very first online lye calculators was created by Majestic Mountain Sage. Soapmakers who are a little bit weak in the math department will love that this calculator does the calculations for you in ounces, pounds, and grams.

    Continue to 5 of 6 below.
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    Miller Soap's Soap Recipe Spreadsheet

    Miller Soap, one of the oldest soap making websites, has a collection of Microsoft Excel spreadsheets to use for creating your own soap recipes. The spreadsheets allow you to customize and save your recipes however you like. Keep a watchful eye on the spreadsheets; many individuals have contributed to this site, so you'll get some repeat calculators.

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    Suds and Scents Lye Calculator

    This is a basic calculator, which makes it a good measurement site for those new to soap making. Like many sites, this one performs calculations in grams and ounces, so there's no need for you to do the conversions, which allows you to spend more time making soap and less time doing math.