HLB Calculator for Emulsifiers

How It Works

HLB (Hydrophilic-Lipophilic Balance) is a numeric scale from 0 to 20 that describes how much a surfactant molecule prefers water versus oil. Values below 8 favor the oil phase and stabilize water-in-oil (W/O) emulsions; values above 10 favor the water phase and stabilize oil-in-water (O/W) emulsions. The mid-range (8-10) is a transitional zone where either type is possible depending on the process.

Every oil has a required HLB — the specific HLB that emulsifies it most stably. Published required HLBs for common carrier oils are: mineral oil ~10, olive oil ~7, jojoba ~6.5, coconut oil ~8, cetyl alcohol ~15, and beeswax ~9 (drawn from the LotionCrafter reference table and Croda's technical library). For a blend of oils, the required HLB is the weight-weighted average:

Required HLB = Σ (oil fraction × required HLB of that oil)

To hit the target, you typically combine a low-HLB emulsifier with a high-HLB one and solve for the ratio. Given two emulsifiers with HLB values A and B (A < target < B) and a target T, the fraction of the low-HLB emulsifier is:

Fraction_A = (B − T) / (B − A)

The tool computes this for common emulsifier pairs (Polysorbate 20 at HLB 16.7, Sorbitan Monostearate at HLB 4.7, Polysorbate 60 at HLB 14.9, Cetearyl Alcohol at HLB 15.5). The math traces to W.C. Griffin's 1949 paper "Classification of Surface-Active Agents by HLB" in the Journal of the Society of Cosmetic Chemists, which is still the foundational reference cosmetic chemists use today.

How to Use This Calculator

1. Select emulsion type — O/W for lotions, creams, sunscreens; W/O for cold creams, some sunscreens.
2. Enter your oil phase — for each oil, its percentage of the oil phase and required HLB. The tool covers 30+ common oils with published values.
3. Read the target HLB — the weight-averaged required HLB updates as you edit the oil list.
4. Choose an emulsifier pair — one high-HLB and one low-HLB from the built-in list.
5. Read the blend ratio — the calculator reports the percentage of each emulsifier to combine.
6. Set the total emulsifier percentage — typically 3-8% of the total formulation, depending on emulsion type and desired stability.

Real-World Use Cases

Simple facial lotion

A formulator building an O/W facial lotion with a 20% oil phase: 50% olive (HLB 7), 30% jojoba (HLB 6.5), 20% cetyl alcohol (HLB 15). Weight-averaged required HLB is (0.50×7 + 0.30×6.5 + 0.20×15) = 6.95. A Polysorbate 20 (HLB 16.7) / Sorbitan Monostearate (HLB 4.7) blend at ratio (16.7 − 6.95) / (16.7 − 4.7) = 81% Sorbitan Monostearate and 19% Polysorbate 20 hits the target closely enough for a stable cream.

Sunscreen-adjacent cream

A cosmetic hobbyist adding 15% zinc oxide to an O/W base with a 25% oil phase (30% shea butter HLB 8, 40% coconut HLB 8, 30% cetyl alcohol HLB 15). Weighted required HLB is 10.1. Zinc oxide favors dispersion in the water phase, so a slightly higher HLB (~11) gives a more stable pigment suspension over shelf life. The formulator adjusts the Polysorbate 60 (HLB 14.9) / GMS (HLB 3.8) blend to about 65% Polysorbate 60.

Massage oil emulsion

A maker producing a 50/50 water-in-oil massage cream with a 60% oil phase of sweet almond (HLB 7), coconut (HLB 8), and beeswax (HLB 9). W/O emulsions need low HLB (target ~5), so the emulsifier blend leans on lecithin (HLB 4) and GMS (HLB 3.8) with a small fraction of higher-HLB emulsifier. The tool reports a 70/30 lecithin/GMS blend at 5% of total formulation.

Tips & Safety Notes

• Add emulsifiers to the oil phase, not the water phase. The HLB system assumes the emulsifier is dissolved in oil when the two phases combine.
• Heat both phases to 70-75 °C before combining. Most emulsifiers work only above their melt point; adding cold emulsifier to hot oil creates lumps.
• Add water phase to oil phase in a slow stream, stirring constantly. Reversing the order in an O/W emulsion often produces a W/O emulsion by accident.
• Cool to 40 °C before adding heat-sensitive ingredients like preservatives, active peptides, and most essential oils.
• Preservation is separate from HLB. A stable emulsion still needs a broad-spectrum preservative for anything above 0.5% water content.

Limitations & What This Tool Cannot Do

• Published HLB values disagree across sources. Different reference tables give slightly different HLB numbers for the same emulsifier; a 1-2 unit variation is common. The tool uses the median of major published tables (Croda, LotionCrafter, W.C. Griffin's original). If your batch behaves unstably, cross-check the emulsifier data sheet.
• Cold-process caveat. HLB math assumes the emulsifier has been fully hydrated and dispersed at temperature. Cold-process emulsions using Olivem 1000, natural gum blends, or ready-made e-wax NF still work but the HLB target may drift by 1-2 units from the theoretical value.
• Formulation, not sensory. HLB predicts emulsion stability, not skin feel, absorption rate, or aesthetic properties. Two emulsions at the same HLB can feel completely different — that comes from the specific oils, thickeners, and humectants, not the HLB.

FAQ

What is HLB (Hydrophilic-Lipophilic Balance) and why does it matter?

HLB is a 0-20 scale describing how strongly a surfactant molecule is pulled to water versus oil. Matching your emulsifier blend's HLB to the oil phase's required HLB is the single strongest predictor of emulsion stability — a mismatched HLB emulsion breaks, phase-separates, or thickens erratically during storage.

What HLB is required for a stable oil-in-water emulsion?

O/W emulsions typically need a blend-average HLB between 8 and 18, depending on the oil phase composition. Light lotions with mineral oil sit around HLB 10-11; heavier creams with fatty alcohols climb to 12-14; oil-blended-with-pigment sunscreens can need 11-13. The specific target is the weight-weighted required HLB of your oil phase.

Can I use a single emulsifier or do I need a blend?

Sometimes a single emulsifier works if its HLB matches the oil phase's required HLB exactly. More often you use a blend of one low-HLB and one high-HLB emulsifier so the ratio can be tuned to any target. Blended emulsifiers also tend to produce more stable emulsions than single ones at the same nominal HLB.

How do I calculate the HLB of a fatty alcohol like cetyl alcohol?

Fatty alcohols and other emulsifying auxiliaries have published HLB values in the same references that list emulsifier HLBs. Cetyl alcohol is typically listed at HLB 15, cetearyl alcohol at 15.5, stearic acid at 15, and glyceryl stearate at 3.8. These enter the required-HLB weighted average like any other oil-phase ingredient.

Why do published HLB values sometimes disagree across sources?

HLB is a semi-empirical scale. Different labs measure it differently (some by calculation from molecular structure, some by empirical emulsification tests), and the values drift by 1-2 units between reference tables. The tool uses the median of major published tables and flags any emulsifier where the published range exceeds ±2 units.

Does HLB work for cold-process emulsification, or only heated systems?

HLB works best for heated systems where both phases are melted and the emulsifier is fully dispersed. Cold-process emulsions using purpose-built cold-process emulsifiers (Olivem 1000, Sepimax ZEN, natural gums) still produce stable emulsions, but the effective target HLB may drift 1-2 units from the theoretical value. Do small test batches when working cold-process.

Related Tools

• Lye & Water Calculator — Same carrier-oil ingredients, different chemistry
• Soap INS Predictor — Same-family fatty acid analytics
• Candle Wax & Fragrance Calculator — Adjacent maker-chemistry tool

References

• W.C. Griffin, "Classification of Surface-Active Agents by HLB," Journal of the Society of Cosmetic Chemists, 1949 — foundational HLB reference
• Croda emulsifier technical data (crodapersonalcare.com/products) — commercial emulsifier HLB values and use notes
• LotionCrafter HLB reference table — required HLB values for common carrier oils

Reviewed by the Craft Calc Lab team on August 1, 2026.