6 Lye Calculators for Cold Process Soap

If you're creating your own soap recipes from scratch, and even if you're using a recipe from a book, a  website, or one you've gotten from a friend, it's crucial to run your recipes through a lye calculator. Using a calculator will make sure that your ratios of water, oils, and lye are correct. Doing so will help ensure that your batch of soap will come out just right and produce the results you were expecting.

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 lye calculators that are easy to access and use. See which one works best for your soap-making needs. 

  • 01 of 06

    New Soap Calc

    Homemade Lye Soap
    Michael Westhoff / Getty Images

    The folks at Soap Calc continue to improve and streamline their online lye calculator. It continues to be one of the best and most comprehensive online lye calculators, plus it offers helpful suggestions and hints. It's a great resource whether you are new to soap-making or an experienced producer.

  • 02 of 06

    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. If cost is an issue, start with the Lite version; you can always upgrade.

  • 03 of 06

    Bramble Berry Lye Calculator

    Bramble Berry's calculator is a great simple 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. 

  • 04 of 06

    Majestic Mountain Sage Lye Calculator

    One of the very first online lye calculators was created by Majestic Mountain Sage. In its earlier versions, the company's offerings got a reputation for having too much water in the recipes, but the Utah firm has corrected that flaw and now offers a range of water usage in the recipes. ​The company also has updated the calculator for sodium lactate. Plus, for the math-challenged, this calculator does the calculations for you in ounces, pounds, and grams.

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  • 05 of 06

    Miller Soap's Soap Recipe Spreadsheet

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

  • 06 of 06

    Suds and Scents Lye Calculator

    This is a very 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. That allows you to concentrate on customizing your scents and sensibilities.