Lye Calculator
Calculate precise NaOH and water amounts for cold-process soap. Supports superfat percentage and water:lye ratio adjustments.
Inputs
Combined weight of all oils/butters in your recipe
Extra oil not converted to soap. 5% is standard; higher = softer, more moisturizing bar
Parts water per part lye. Lower = faster trace & harder bar. 2.33:1 is standard
Use your oil blend's weighted SAP value
Results
Batch composition by weight
Lye Calculator
Artisan by Irora Labs
March 23, 2026
Inputs
| Total Oil Weight | 1000 g |
| Superfat % | 5 % |
| Water:Lye Ratio | 2.33 |
| Weighted SAP Value | 0.141 |
Results
| NaOH (Lye) | 133.9g |
| Water | 312.1g |
Created with Artisan. artisan.iroralabs.com/craft-calculators/lye
Tips
Open formula
Uses the saponification value of your oil blend to calculate sodium hydroxide needed, with superfat reduction for skin-safe soap.
Saponification values from Bramble Berry and Soap Queen references
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