Soap & Lotion Tools
16 free calculators for soap and lotion makers — lye, batch scaling, molds, costs, fragrance rates, lotion formulas, and more. No signup, no cost.
Lye Calculator
Exact NaOH and KOH amounts for any oil blend, with superfat control and soap quality predictions.
Calculate lye →Soap Mold Calculator
Measure your mold and get the exact oil weight your recipe needs to fill it — no overflow, no short batches.
Size your mold →Soap Cost & Profit Calculator
True cost per bar from ingredients, labor, and overhead — plus wholesale and retail pricing with profit at each level.
Price your soap →Soap Fragrance Calculator
Exact fragrance oil amounts by usage rate for cold process, hot process, melt & pour, liquid soap, and lotion.
Measure fragrance →Lotion Formulation Calculator
Turn percentage formulas into gram weights by phase, with starter templates and a preservative safety check.
Formulate lotion →HLB Emulsifier Calculator
Find your oil phase’s required HLB, then blend two emulsifiers to match it for a stable, non-separating lotion.
Blend emulsifiers →Soap Cure Date Calculator
Enter your batch date and method to see exactly when your soap is ready to use, gift, or sell.
Find your cure date →Soap Batch Resizer
Scale any soap recipe up or down — by factor or to a target batch weight — with every ingredient recalculated.
Resize a batch →Lye Masterbatch Calculator
Pre-mix 50% lye solution and use it in any recipe — how much to make, and how much each batch needs.
Masterbatch lye →Lye Concentration Converter
Convert between water as % of oils, lye concentration %, and water:lye ratio — plus a water-discount finder.
Convert water & lye →Soap Additive Calculator
Salt, sodium lactate, sugar, clays and more — amounts by % of oil weight with typical usage rates.
Measure additives →Liquid Soap Dilution Calculator
Dilute KOH soap paste to the perfect consistency — water amounts, finished yield, and bottle count.
Dilute liquid soap →INCI Name Lookup
Find the correct legal label name for the oils, butters, colorants, essential oils, and additives in your soap recipe.
Look up names →Soap Colorant Calculator
Figure out how much mica, oxide, ultramarine, titanium dioxide, charcoal, clay, or cocoa powder your batch needs — light, medium, or deep shades.
Calculate colorant →Rebatch Calculator
Rescue seized or ugly soap — grate it down and find exactly how much liquid to add for hand-milling, with conservative and maximum amounts.
Calculate liquid →Cure Weight Tracker
Weigh your bars over the cure and watch the water evaporate — know exactly when your soap is truly ready. Saves in your browser automatically.
Track your cure →
