Soap Calculator: Lye & Recipe
Saponification & Cure Tracker
Free · In‑App Purchases · Designed for iPad. Not verified for macOS.
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/
Smoother and more reliable throughout, with groundwork for smarter improvements based on how makers actually use the app.
The developer, Panda Taps LLC, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Panda Taps LLC
- Size
- 9.1 MB
- Category
- Lifestyle
- Compatibility
Requires iOS 18.6 or later.
- iPhone
Requires iOS 18.6 or later. - iPad
Requires iPadOS 18.6 or later. - Mac
Requires macOS 15.6 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 2.6 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Trace Pro Lifetime $9.99
- Trace Pro Yearly $8.99
- Trace Pro Monthly $3.99
- Copyright
- © 2026 Panda Taps LLC