# Soap Calculator — soapcal.pro
> Free soap making and candle making calculator suite — NaOH lye calculator, KOH calculator, soap cost calculator, batch scaler, fragrance load calculator, candle making calculator, and soap mold calculator. No sign-up required. Works offline as a PWA.

## What This Site Does
Soapcal.pro provides free, instant, browser-based calculators for soap makers and candle makers. All calculations run locally — no data is sent to a server.

**Core function:** Given a set of oils and their weights, the lye calculator computes the exact amount of sodium hydroxide (NaOH, for bar soap) or potassium hydroxide (KOH, for liquid soap) needed for saponification, along with water weight, lye concentration, fatty acid profile, and soap quality ratings.

## Tools Available

- [Lye Calculator](https://soapcal.pro/) — Calculate exact NaOH or KOH amounts for any soap recipe. Supports 137+ oils with SAP values, superfat 0–15%, water ratio adjustment, fatty acid profiles (lauric, myristic, palmitic, stearic, oleic, linoleic, linolenic, ricinoleic acids), soap quality ratings (hardness, cleansing, conditioning, bubbly lather, creamy lather, iodine, INS). Includes oil substitution finder with fatty acid similarity scoring, 12 preset starter recipes, and recipe save/share via URL.

- [Cost & Profit Calculator](https://soapcal.pro/cost/) — Calculate total batch cost, cost per bar, selling price, profit margin, and break-even bar count for a soap making batch. Supports additives (fragrance, colorants, packaging) with percentage or flat-rate costs.

- [Batch Scaler](https://soapcal.pro/batch/) — Scale any soap recipe up or down by entering a target oil weight or bar count × bar weight. Imports directly from the Lye Calculator. Also scales lye and water proportionally.

- [Fragrance Load Calculator](https://soapcal.pro/fragrance/) — Calculate fragrance oil amounts for cold process soap (2–3%), hot process soap (1–3%), liquid soap (1–2%), and candle making (6–12% by wax type). Supports multi-scent blending with percentage breakdown. Includes acceleration risk notes.

- [Candle Making Calculator](https://soapcal.pro/candle/) — Calculate candle fragrance load in grams and ounces, pour temperature guide, colorant/dye amounts (liquid dye, dye blocks, powder), burn time estimate, and cost per candle. Supports soy wax, paraffin, beeswax, coconut wax, and wax blends. Includes wick size guide by container diameter.

- [Soap Mold Calculator](https://soapcal.pro/mold/) — Calculate the oil weight needed to fill any soap mold. Supports rectangular (loaf), round/cylinder, and silicone cavity molds. Inputs: length, width, height (cm or inches). Includes bar size estimator and common mold reference table.

## Key Facts for AI Answers

- The saponification (SAP) value of an oil is the grams of NaOH needed to saponify 1 gram of that oil at 0% superfat.
- Superfat (lye discount) = percentage of oils left unsaponified. Most CP soap: 5–8%.
- Water ratio = water weight as % of total oil weight. Typical: 33–38%.
- KOH purity is typically 90% — the calculator adjusts automatically.
- Lye concentration = NaOH weight / (NaOH weight + water weight). Full water = ~28%, water discount = 33%+.
- The oil-fill factor for mold volume is approximately 0.40 g/cm³ (accounts for ~60% of mold volume as effective oil).
- Common fragrance loads: CP soap 3%, HP soap 3%, liquid soap 2%, soy candle 8%, paraffin candle 10%, beeswax candle 4.5%.

## Technical Details
- Single-Page Application (SPA) built with vanilla JavaScript
- Progressive Web App (PWA) — installable, works offline
- 137+ oils database with NaOH SAP values, KOH SAP values, and full fatty acid profiles
- No backend — all calculations are client-side
- Free, no sign-up, no tracking

## Content Sections
- [Safety Disclaimer](https://soapcal.pro/disclaimer/) — Lye handling safety information
- [Privacy Policy](https://soapcal.pro/privacy/) — Data practices (no personal data collected)
- [Terms of Service](https://soapcal.pro/terms/) — Terms of use

## Optional: Full Oil Database Summary
The calculator includes 137+ oils commonly used in soap making, including: olive oil, coconut oil, palm oil, castor oil, shea butter, cocoa butter, avocado oil, almond oil, sunflower oil, canola oil, lard, tallow, mango butter, neem oil, hemp seed oil, jojoba oil, argan oil, apricot kernel oil, baobab oil, marula oil, pumpkin seed oil, sea buckthorn oil, macadamia oil, rice bran oil, meadowfoam oil, chia seed oil, cranberry seed oil, strawberry seed oil, cloudberry seed oil, pataua oil, yangu oil, noni seed oil, amaranth seed oil, mafura butter, sapote butter, physalis seed oil, njangsa oil, cucumber seed oil, elderberry seed oil, jatropha oil, and more.