Cold process soap calculator · guided recipe builder

Choose a recipe. Then customize it.

Start from a beginner recipe template, scale the oils, change ingredients or prices, and the calculator updates lye, water, fragrance, salt, and cost per bar.

1. Starter recipe

Choose a recipe from the dropdown. It loads immediately. The numbers are there so you can learn by changing them.

Recipe scale:g oils

Step 1 · Pick a recipe

The dropdown gives you a safe starting structure instead of a blank spreadsheet.

Step 2 · Customize slowly

Change one thing at a time: total oil weight, oil percentages, fragrance, cost, or salt.

Step 3 · Check warnings

The warnings flag coconut over 25%, soft liquid-oil recipes, used oil, and suspicious SAP values.

Why do calculations appear immediately?

The app opens with a real starter recipe so a beginner can see how lye, water, fragrance, salt, and cost respond when the recipe changes. Choose another recipe from the dropdown or edit the oil table directly.

2. Batch settings

Most hard bars use NaOH.

Beginner default: 5%.

30% gives beginners more working time.

Use 100 unless your supplier says otherwise.

Check supplier/IFRA limits.

For costing only.

3. Salt for hardness

Salt is optional. It may help a soft recipe harden, but it does not change the lye amount.

Off by default. Turn on for a suggested amount.

Beginner rule of thumb: 1 tsp/lb oils.

Approximation for fine table salt.

Optional for costing.

4. Oils and fats

Use presets, or type a custom oil and enter SAP values manually.

PresetOil / fat nameGrams%NaOH SAPKOH SAPPrice / kgUsed?

5. Costing

Advanced costing