Soap Calculator: Lye & Recipe

Soap Calculator: Lye & Recipe

Saponification & Cure Tracker

8 ratings
5 reviews
Free
In-App Purchases

Details

  • Released
  • Updated
  • May 26, 2026
  • August 24, 2026

Features

Soap Calculator: Lye & Recipe screenshot #1 for iPhone
Soap Calculator: Lye & Recipe screenshot #2 for iPhone
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Soap Calculator: Lye & Recipe screenshot #9 for iPhone
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About

This app helps handmade soap makers calculate precise lye and water weights for various soap types. It provides detailed fatty-acid profiles, predicted bar properties, and generates FDA-style ingredient labels. It also includes batch tracking and a cure timer with lock screen widgets.

Lye and water weight calculation
200+ verified oils with saponification values
Predicted bar properties and fatty-acid profile
FDA-style INCI ingredient label generation
Batch saving with notes and photos
Cure timer with Dynamic Island and Lock Screen support
On-device AI for label copy
Show original description

What's New in Soap Calculator

1.7

August 24, 2026

ADDITIVES Clays, milks, oatmeal, micas and your own ingredients. They sit in the recipe, price into your cost per bar, and come off your shelf the moment you pour. MILKS AND LIQUIDS Goat milk, coconut milk and brewed coffee dose against the water they replace, not the oils. COST PER BAR Labels, packaging, labor, overhead and every ingredient in one honest number you can price against. PRINTING Recipe sheets, batch worksheets and one-page GMP batch records. VERSIONS Save a formula before you change it and compare any two side by side. Duplicate one and the additives, fragrance and costing come with it. TRACEABILITY Supplier, lot, IFRA ceiling and cost, frozen the day you pour and never rewritten. UNITS Ounces, grams or pounds, held on every screen, every printed sheet and every batch record. 24 MORE OILS Canola among them. Search for one the catalog does not carry and it offers to add it.

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Subscription plans

Trace Pro Monthly

The full app, billed monthly. 3-day trial.

$3.991 Month
How to cancel Soap Calculator subscription ⁉️
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In-App Purchases

$14.99

Trace Pro Lifetime

The full app, forever. One-time purchase.

User reviews

Add additives list

I’m really enjoying the app! The recipe calculator, batch tracking, curing notifications, inventory, and shopping list are incredibly useful.

One feature I would LOVE to see added is an Additives section within each recipe. It would be great to add ingredients such as kaolin clay, sodium lactate, colloidal oatmeal, activated charcoal, sugar, salt, micas/colorants, milks, etc., with the option to enter the amount in grams, ounces, or as a percentage of oils.

Even better if additives could be connected to inventory and recipe costing, so the app can calculate the true cost of each batch and automatically deduct them from stock when a batch is made.

That would make this an amazing all-in-one app for small soap businesses. I would absolutely love to see this feature in a future update!
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Response from developer

Thank you - and good news: this is exactly what version 1.7 is, and it is out now. Every recipe has an Additives section. Kaolin, sodium lactate, colloidal oatmeal, activated charcoal, sugar, salt, micas and milks, entered in grams, ounces or percent of oils. Milks, coffee and other liquids dose against the water they replace rather than the oils, so the lye math stays right. They are wired into inventory and costing, exactly as you described. A batch shows its true cost per bar, and the amounts come off your stock the moment you pour. You can add your own ingredients too, with supplier and unit cost.

Settings

In the settings I had it set to calculate in grams, but it would only show everything in ounces. I got frustrated that nothing I did would change it so I deleted it and canceled the free trial.

Response from developer

Thank you for reporting this, and we're sorry for the frustration. You found a genuine defect: the unit preference was saving correctly, but the calculator and recipe screens were not reading it. Nothing you tried could have resolved it. This is fixed in the next update, where grams, ounces and pounds carry through the batch size, every oil, the water and the lye. That update also adds an expanded oil catalogue including canola, an additives section for clays, sodium lactate, charcoal, micas and milks, printable recipe and batch sheets, fuller fragrance tracking with supplier and IFRA limits, costing that covers additives, fragrance, packaging and labels, custom ingredients, and recipe versioning. We'd welcome the opportunity to earn a second look. Thank you!

Missing Oils?

I cannot find Canola Oil in the drop down of “200 oils” in the database. Am I missing something?

Response from developer

You're not missing anything - canola isn't in the current catalogue. It's added in the next update, along with corn, cottonseed, peanut, wheat germ and about twenty more. If you need it before then, canola's saponification value is 0.133 NaOH (0.186 KOH), so you can work the lye by hand in the meantime. Sorry for the inconvenience.

Simple and Accurate

Great soap calculator! Easy to use, accurate lye calculations, and helpful for planning recipes with confidence.

New Soap Maker

This is making my new hobby so much easier to start. I’ve planned on making my family soap for years but was intimidated by. This gives me step by step directions

Developer apps

FAQ

What types of soap can Soap Calculator handle?

Soap Calculator supports cold-process, hot-process, melt-and-pour, and liquid soap recipes. It can calculate lye weights for both NaOH (solid bars) and KOH (liquid soap).

How does Soap Calculator ensure safety when dealing with lye?

Lye numbers are framed as safety calculations on every screen, highlighting hazards, required protective equipment, and safe-handling sequences in dedicated safety-red callouts.

Can I generate ingredient labels with Soap Calculator?

Yes, the app generates FDA-style INCI ingredient labels, including lot numbers and manufacture dates. Labels can be exported as PDFs ready for printing on Avery 5160 sheets.

How does the cure timer work in Soap Calculator?

The cure timer is integrated with your device, appearing in the Dynamic Island and on your Lock Screen. You'll receive a notification the morning a batch is ready.

Does Soap Calculator collect any personal data?

No, Soap Calculator is designed with privacy in mind. It has no accounts, no backend, no analytics, and no tracking. All data lives on your device, and a Privacy Manifest declares zero data collection.

What are the pricing options for Soap Calculator Pro?

Soap Calculator Pro offers a monthly subscription at $1.99, a yearly subscription at $4.99, or a one-time Lifetime purchase at $9.99. All subscription plans include a 3-day free trial.

How often is Soap Calculator updated?

The app was last updated on June 23, 2026, with version 1.1. This indicates a recent update, suggesting ongoing development and support.

What is the user sentiment for Soap Calculator?

Based on the provided data, Soap Calculator has a perfect rating of 5.0 stars from 5 ratings, indicating extremely positive user sentiment.