Soap Calculator: Lye & Recipe

The soap maker's studio: exact lye math, cure timers in your Dynamic Island, FDA-ready labels, batch records, and AI that turns recipe photos into batches. All offline.

Soap Calculator: Lye & Recipe is the lye and soap calculator built for handmade soap makers - cold-process, hot-process, melt-and-pour, and liquid soap.

Type your oil blend, batch size, water and superfat percentages, and the app returns the exact lye weight (NaOH for solid bars, KOH for liquid soap), a water weight, a saponification check, predicted bar properties, and a full fatty-acid profile - before you ever pour.

THE CALCULATOR

• 200 oils, each with a verified saponification value, fatty-acid breakdown, and INCI saponified name
• NaOH and KOH - solid bars or liquid soap
• Superfat 0 to 15 percent, water at any percentage of oil weight
• Predicted bar properties: hardness, cleansing, conditioning, bubbly and creamy lather, plus iodine and INS
• A fatty-acid blend ribbon that shifts in real time as you adjust the recipe

SAFETY FIRST Lye is caustic. Every screen that shows a lye number frames it as a safety calculation - the hazard, the protective equipment, the safe-handling sequence - in a dedicated safety-red callout.

LABELS THAT SELL

• FDA-style INCI ingredient labels
• Avery 5160 print sheets - 30 labels per page
• Lot numbers and manufacture dates on every label
• Export as PDF, ready for the printer

BATCHES AND CURE TRACKING

• Save unlimited recipes and batches with notes and photos
• A cure timer that lives in the Dynamic Island and on your Lock Screen
• Home Screen widgets for your active batch
• A notification the morning a batch is ready

ON-DEVICE AI The optional AI label copywriter uses Apple's on-device models - your recipes and notes never leave your iPhone.

PRIVACY BY DESIGN No accounts. No backend. No analytics. No tracking. No ads. A Privacy Manifest declares zero data collection - everything lives on your device.

Lifetime unlocks the whole app: a one-time Lifetime purchase at $9.99.

Privacy Policy: https://www.pandataps.com/legal/trace-privacy.html Terms of Use: Apple's Standard EULA: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/