How to Use DecodeMath

INCI Label Reverse Engineer — Estimate Ingredient Percentages & Identify Blends

DecodeMath is a label reverse-engineering tool. Give it the INCI ingredient list from any cosmetic product label — in label order — and it estimates percentage ranges for each ingredient, identifies trade-name composite blends, tags functional categories (humectant, emulsifier, preservative, active), marks the ≤1% zone, and generates a Formula Analysis with a phase breakdown chart and pH recommendation.

At a Glance

How INCI Order Maps to Concentration

Cosmetic ingredients must be listed in descending order of concentration (by weight at time of manufacture) in the EU, US, and most other regulated markets — with one important exception.

Top of the List = Highest Concentration

Aqua (Water) appearing first means it's the largest ingredient by weight — typically 60–90% in most emulsions. The first five to ten ingredients usually account for the vast majority of the formula.

The ≤1% Exception

Ingredients present at 1% or less may be listed in any order after the above-1% ingredients. Colorants (in the EU) are also exempt. This means the bottom of a label is not strictly ordered — a preservative at 0.8% and a fragrance at 0.01% may appear side by side with no indication of which is greater.

What DecodeMath Does With This

DecodeMath estimates the likely ≤1% cutoff based on position in the list and ingredient type. Ingredients that are almost always used at ≤1% (preservatives, chelators, colorants, specialty actives) are flagged accordingly. Ingredients that can appear at any level (emollients, humectants) are estimated from context.

Step-by-Step: Using DecodeMath

Copy the INCI List from the Label

Find the full ingredient declaration on the product label or the brand's website. Copy it exactly as listed. INCI names are typically in all caps or title case — Aqua, Glycerin, Cetearyl Alcohol, Phenoxyethanol, etc.

Enter Each INCI Name in Order

Add ingredients one per row in DecodeMath, maintaining the original label order. The order is essential — the engine uses position to estimate concentration ranges. Use the official INCI name rather than the common name for best match results.

Pro Tip

If you're not sure of the correct INCI spelling, search the ingredient in the SoapMath Encyclopedia. The encyclopedia shows the official INCI name for every ingredient in the database.

Review Estimated Percentage Ranges

DecodeMath assigns each ingredient an estimated % range based on its position, functional category, and known typical usage. Ranges are wider for ingredients with variable usage (carrier oils can be 1–30%) and narrower for ingredients with established norms (Phenoxyethanol is almost universally 0.5–1%).

Check for Identified Composite Blends

Adjacent INCI names that match a known composite blend are highlighted with a badge showing the likely trade name. For example, "Phenoxyethanol (and) Caprylyl Glycol" is identified as Optiphen. The blend is shown as a single unit with its full component list and combined function.

Read the Function Labels

Every ingredient row shows a function badge — Humectant, Emollient, Emulsifier, Surfactant, Thickener, Chelator, Preservative, Active, Fragrance, Colorant. These come from the ingredient database and help you understand the structural role each ingredient plays.

Review the Formula Analysis

Scroll to the Formula Analysis section below the ingredient list for three outputs:

Phase Breakdown Chart: Bar chart showing estimated distribution across water phase, oil phase, emulsifiers, actives, and preservation system.
pH Recommendation: Based on detected actives (Vitamin C suggests pH 2.5–3.5; Niacinamide suggests pH 5–7; AHAs suggest pH 3–4).
System Callout Cards: Identifies the preservative system, emulsifier system, and key actives at a glance.

What DecodeMath Can and Cannot Tell You

What It Can Tell You

Which ingredient category each INCI belongs to
Rough percentage ranges (wider for variable ingredients, narrower for standardized ones)
Whether a set of adjacent INCIs is a known composite trade-name blend
The likely ≤1% zone boundary
The product's phase architecture (water-heavy, oil-heavy, emulsion, etc.)
Which preservative system is most likely in use

What It Cannot Tell You

Exact percentages — those are proprietary and not deducible from the label
Processing conditions, temperature steps, or manufacturing method
Whether the product is stable, effective, or safe at the specific percentages used
Ingredients not listed (allergens below labeling threshold, impurities)

Composite Blend Recognition

Many cosmetic ingredients sold as single trade-name products are actually blends of two or more INCI-listed components. A label must declare all components individually, which means a single trade-name product can appear as two, three, or four adjacent INCI entries. DecodeMath recognizes common blends by scanning for adjacent INCI sequences that match its composite database.

Trade Name	INCI Components	Function
Optiphen	Phenoxyethanol (and) Caprylyl Glycol	Preservative
Optiphen Plus	Phenoxyethanol (and) Caprylyl Glycol (and) Sorbic Acid	Preservative
Phenonip	Phenoxyethanol (and) Methylparaben (and) Ethylparaben (and) Butylparaben (and) Propylparaben (and) Isobutylparaben	Preservative
Euxyl PE 9010	Phenoxyethanol (and) Ethylhexylglycerin	Preservative
Germall Plus	Diazolidinyl Urea (and) Iodopropynyl Butylcarbamate	Preservative
Olivem 1000	Cetearyl Olivate (and) Sorbitan Olivate	Emulsifier

Tips for Best Results

Use the Label's INCI Order Exactly

Any reordering changes the concentration estimates. If you're copying from a website that reformatted the label, double-check against the physical product or the brand's official ingredient declaration.

Include Every Ingredient

Leaving out ingredients — even ones you don't recognize — shifts the ≤1% boundary estimate and can change composite blend detection if adjacent names are removed. Enter the complete list for the most accurate output.

Don't Use DecodeMath Output as a Recipe

The percentage ranges are estimates, not the manufacturer's actual formula. Use the output to understand the product's structure, then build and validate your own version using AquaMath, LotionMath, or BalmMath depending on the product type.

Cross-Reference with the Encyclopedia

If an ingredient isn't recognized by DecodeMath, search it in the SoapMath Encyclopedia. The encyclopedia contains ~500 ingredients with INCI names, typical usage rates, solubility, function, and compatibility notes that can help you place the ingredient manually.

Pro Tip

DecodeMath is useful for competitive benchmarking — understanding what category of product a competitor's formula is (emulsion, water gel, serum), which preservative system they chose, and where they positioned their actives. This is market research, not recipe copying.

Frequently Asked Questions

Try it now: open DecodeMath

Grab any product label from your bathroom shelf and enter its INCI list to see how DecodeMath maps the formula structure.

Open DecodeMath →