Which Calculator Should I Use?
Every tool in the SoapMath suite — what it does and when to use it
SoapMath has seven specialized calculators, each designed for a different type of cosmetic product. The key question is always: does your product contain water? and is the base soap, emulsion, anhydrous, or surfactant? Those two questions get you to the right calculator almost every time.
Quick Decision Guide
- Making something with lye (NaOH or KOH)? → SoapMath
- Making a lather-producing liquid cleanser? → BubbleMath
- Making a lotion, cream, or conditioner (has both oil and water)? → LotionMath
- Making a balm, butter, or oil product (no water)? → BalmMath
- Adding colorants to a formula? → ColorMath (alongside your main calculator)
- Scaling a formula or converting % to grams? → BatchMath
- Checking fragrance safety limits? → IFRA Math
SoapMath 🧼
Bar soap (cold process, hot process), liquid soap (KOH), cream soap (dual lye), and shaving soap.
Use for:
- Cold process bar soap
- Hot process bar soap
- Cold process liquid soap
- Cream soap (dual NaOH + KOH)
- Shaving soap
- Laundry soap bars
Not for: body wash, shampoo, lotion, or any product without lye-saponification chemistry.
LotionMath 🧴
Emulsions containing both water and oil phases — anything that requires an emulsifier to hold together.
Use for:
- Body lotion and body cream
- Face moisturizer
- Hand cream
- Hair conditioner (W/O)
- Leave-in conditioner
- Facial serum (water-based)
- Toner and essence (with emollients)
Not for: anhydrous products (no water), cleansers, surfactant-based products.
BalmMath 💄
Anhydrous (water-free) products made from oils, butters, and waxes. No emulsification needed.
Use for:
- Lip balm
- Body balm / solid lotion bar
- Whipped body butter
- Salve and healing balm
- Oil serum
- Facial oil blend
- Perfume roller (oil-based)
- Cleansing balm / makeup remover balm
- Sugar/salt scrub oil base
Not for: water-containing products, surfactant-based products, or soap.
BubbleMath 🫧
Surfactant-based liquid cleansers. Calculates active surfactant mass (ASM) and formulation architecture.
Use for:
- Body wash
- Liquid hand soap
- Shampoo
- Face wash / cleanser
- Bubble bath
- Foaming hand soap (pump)
Not for: bar soap (use SoapMath), lotion (LotionMath), or water-only products.
ColorMath 🎨
FDA-approved colorant mixing and usage calculations. Combines with any other calculator.
Use for:
- Soap colorants
- Lotion and cream colorants
- Lip color blends
- Color mixing ratios
Use alongside your main calculator — not a standalone formula builder.
BatchMath ⚖️
Scales any formula from percent to weight, or resizes a recipe. Works with any product type.
Use for:
- Scaling a % recipe to batch size
- Resizing an existing batch up or down
- Converting between grams and ounces
BatchMath doesn't check chemistry — it just scales weights. Use it after your other calculator confirms the formula.
IFRA Math 🌸
Fragrance compliance against IFRA (International Fragrance Association) category limits.
Use for:
- Fragrance usage rates for any product type
- Multi-component fragrance blend analysis
- Restricted ingredient checks
Not for: colorants, preservatives, or non-fragrance ingredients. Check your fragrance supplier's IFRA certificate for the inputs.
Frequently Asked Questions
Tip: All calculators are free
SoapMath, LotionMath, BalmMath, BubbleMath, BatchMath, ColorMath, and IFRAMath are all free to use.