Soap Lye Calculator
Enter each oil name, weight, and independently verified SAP value, then select NaOH or KOH. The calculator applies superfat, product purity, and either lye concentration or water-to-alkali ratio.
How to use this calculator
Enter matching oil names, weights, and verified SAP values, alkali type, superfat, purity, and water method.
Review supplier NaOH SAP values, NaOH purity, measurement accuracy, additives, process method, personal protective equipment, and safe handling procedure.
Read oil percentages, per-oil alkali demand, selected alkali, pure and product alkali mass, water mass, and resulting concentration.
Formula
Pure alkali = Σ(oil weight × matching NaOH or KOH SAP) × (1 − superfat). Product mass = pure alkali ÷ purity; water follows entered lye concentration or water-to-alkali ratio.
Worked example
For 500 g of an oil with NaOH SAP 0.135, theoretical NaOH is 67.5 g; 5% superfat reduces the modeled amount to 64.125 g before purity adjustment.
Assumptions and limits
- NaOH and KOH are strongly corrosive. All SAP values are user-supplied and must be independently verified; this arithmetic is not a handling, mixing, recipe, or finished-soap safety procedure.
- Soap Lye Calculator treats the entered values as estimates and does not infer missing project, account, or personal details.
- Calculations retain working precision except where the cited method requires an intermediate rounding step; displayed values are then formatted separately. Source rules and dated rates must be rechecked when they change.
Sources
- Centers for Disease Control and Prevention: Sodium Hydroxide: NIOSH Pocket GuideSodium hydroxide hazards and exposure precautions. Reviewed 2026-08-14.
- National Institute of Standards and Technology: SI Units — LengthLength, area, volume, and unit-conversion conventions. Reviewed 2026-08-14.
- National Institute for Occupational Safety and Health: NIOSH Pocket Guide to Chemical Hazards — Potassium HydroxideOfficial formula or method source used by this calculator. Reviewed 2026-08-14.
Related calculators
Verification
How this calculator is checked
Trust comes from reproducible evidence, not model confidence. You can inspect the formula, assumptions, worked example, and cited sources on this page.
- Versioned calculationFormula logic is kept separate from the interface and covered by automated registry and behavior checks.
- Cited evidenceSources linked for independent checking: 3.
- Transparent AI useAI may assist drafting or adversarial review. Agreement between models is not proof, and no human expert review is claimed unless a named reviewer is shown.
Frequently asked questions
How does the Soap Lye Calculator work?
Pure alkali = Σ(oil weight × matching NaOH or KOH SAP) × (1 − superfat). Product mass = pure alkali ÷ purity; water follows entered lye concentration or water-to-alkali ratio.
What information should I enter in the Soap Lye Calculator?
Enter matching oil names, weights, and verified SAP values, alkali type, superfat, purity, and water method, then verify supplier NaOH SAP values, NaOH purity, measurement accuracy, additives, process method, personal protective equipment, and safe handling procedure.
What should I verify before using this Soap Lye Calculator result?
NaOH and KOH are strongly corrosive. All SAP values are user-supplied and must be independently verified; this arithmetic is not a handling, mixing, recipe, or finished-soap safety procedure.
Last updated 2026-08-25 · oil-rows-alkali-water-2.0.0 · content-2026-08-14 · Published by YunFanLabs