Calculate precise NaOH or KOH amounts, water ratios, and 7 soap quality metrics for cold process, hot process, and liquid soap recipes. Includes cure time estimates.
Oils & Fats
Lye Type
NaOH
80.4g
Water
209.0g
Total
839g
Estimated cure time: 6-9 weeks
SAP values sourced from industry databases. Always verify with your supplier's specifications.
Understanding the science behind your soap recipe helps you create better, more consistent results.
Every oil has a saponification (SAP) value that tells us exactly how much lye is needed to convert it into soap. Our calculator uses verified SAP values for each oil to determine the precise lye amount for your recipe.
Superfatting reduces the lye below 100% to leave free oils for moisturizing. Water dissolves the lye and controls the consistency of your soap batter. We calculate both based on your chosen percentages.
We calculate 7 quality metrics from the weighted fatty acid profile of your oil blend. These predictions help you balance hardness, lather, conditioning, and shelf stability before you make a single batch.
7 quality metrics calculated from the fatty acid profile of your oil blend.
Ideal: 29-54
How long your bar lasts. Controlled by lauric, myristic, palmitic, and stearic acids.
Ideal: 12-22
How effectively the soap strips oils from skin. Driven by lauric and myristic acids.
Ideal: 44-69
How moisturizing and gentle the soap feels. From oleic, linoleic, and ricinoleic acids.
Ideal: 14-46
Size and fluffiness of the lather. Lauric, myristic, and ricinoleic acids contribute.
Ideal: 16-48
Richness and stability of the foam. Created by palmitic, stearic, and ricinoleic acids.
Ideal: 41-70
Predicts shelf life. Lower values mean less unsaturation and better resistance to rancidity.
Ideal: 136-170
Overall balance score combining hardness and iodine. Values in range indicate a well-rounded bar.
The free version is great for one-off recipes. Inside Formuley, it becomes part of your full formulation workflow.
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