Soap Recipe Calculator
Calculate lye and water amounts for cold process soap making based on your oil weight.
How to Use the Soap Recipe Calculator
- Enter the total weight of oils in your recipe in grams.
- Enter your desired lye concentration (default 33%).
- Click Calculate to get lye and water amounts.
- Always add lye to water — never water to lye — when making soap.
Casos de Uso
- •Planning cold process soap batches.
- •Scaling soap recipes up or down.
- •Teaching soap-making fundamentals.
- •Estimating material needs for handmade soap businesses.
Fórmula
Lye (NaOH) = Oil Weight × 0.135 (average SAP value). Water = (Lye / Lye Concentration%) − Lye. Total Batch = Oil + Lye + Water.
Perguntas Frequentes
What is SAP value?
The saponification (SAP) value is the amount of lye needed to fully saponify a given oil. Different oils have different SAP values. This calculator uses an average of 0.135 for a typical oil blend.
What lye concentration should I use?
A 33% lye concentration (the default) is standard for cold process soap. A higher concentration means less water, which speeds up trace and reduces the risk of soda ash.
Is this calculator safe to use for actual soap making?
This is a simplified estimate using an average SAP value. For precise recipes with specific oils, use a dedicated lye calculator with individual oil SAP values.