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HLB calculator

An oil-in-water emulsion holds best when its emulsifiers’ HLB matches the one its oil phase requires. Give the oil phase for its required HLB, from ICI’s published table, then pick two emulsifiers for the ratio that meets it.

The oil phase
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The emulsifiers
Optional: the two together, to split between them.

fill in the oil phase

Calculated at soapformulator.com, every value sourced. Check the figures against your own scale.

The formula, and where it comes from 
required HLB of the phase = Σ(shareᵢ × required HLBᵢ) ÷ Σshareᵢ   # over the oils with a figure
share of the high-HLB emulsifier = (target − HLB_low) ÷ (HLB_high − HLB_low)
blend HLB = share_low × HLB_low + share_high × HLB_high
  • W. C. Griffin, "Classification of Surface-Active Agents by HLB", Journal of the Society of Cosmetic Chemists 1 (1949) 311–326; and "Calculation of HLB Values of Non-Ionic Surfactants", JSCC 5 (1954) 249–256. — Defined for non-ionic surfactants only. An ionic or polymeric emulsifier has no HLB in this sense.
  • The HLB of a blend is the mass-weighted mean of its components’ HLB values: HLB_blend = Σ(wᵢ × HLBᵢ) ÷ Σwᵢ. This additivity is the property that makes blending to a target possible and is stated in Griffin (1954).
  • The required HLB of an oil is determined experimentally and published in supplier and handbook tables; the required HLB of a mixed oil phase is the mass-weighted mean of the components’ values. — Published required-HLB values for the same oil differ between sources, often by a point or more, and depend on whether the emulsion is oil-in-water or water-in-oil. Treat a match as a starting formulation, not a specification.
  • Working convention: an emulsifier blend within about ±1 HLB unit of the oil phase’s requirement is treated as matched, since that is the width of the disagreement between published tables for a single oil. — A convention of the craft, not a measured threshold.

A worked oil phase

The oil phase the page starts with, 30 % jojoba oil, 20 % cocoa butter, 20 % cetyl alcohol, 20 % castor oil and 10 % beeswax, requires an HLB of 10.0. Sorbitan stearate and polysorbate 60, ICI’s own example pair, meet it at 49 % to 51 %; the table beside the result gives the ratio for every other family that can.

What the number means

HLB, Griffin’s hydrophile–lipophile balance, runs from 0 to 20 and says how water-loving a non-ionic emulsifier is. Each oil has a required HLB: the emulsifier HLB that holds it best in an oil-in-water emulsion. A phase of several needs the weighted mean of theirs, and a blend of emulsifiers gives the weighted mean of theirs, so matching the two is arithmetic.

Within about one

ICI gives its figures as approximately ± 1, for emulsions of 20 % or less of the material, and says they vary with the source of an oil, its concentration and the method of making. A match is a starting point to test, not a promise of stability. The figures are for oil-in-water emulsions only: water-in-oil ones need 3 to 8 whatever the oil.

Creams are made thicker on purpose

For a thick cream, ICI notes that makers use more of a low-HLB emulsifier than the match calls for, such as a stearic acid soap or sorbitan stearate, for its thickening, so the blend’s HLB ends up below the oil phase’s. The figure here is for a pourable lotion.

Oils the table does not cover

Oils with no published figure can go in the phase: the page leaves them out of the figure and says how much of the phase it covers. ICI’s way to find an oil’s own figure is a row of small test emulsions, each with a blend one HLB apart, to see which separates last.

For a whole formula, with the water phase and preservative, use the lotion calculator.

Where these numbers come from

ICI Americas Inc., Wilmington, Delaware — The HLB System: a time-saving guide to emulsifier selection, Table 2A "Required HLB for O/W Emulsions of a Variety of Emulsion Ingredients (Approx. ± 1)" · document dated 1984 · read 2026-09-22

Chapter 2. The table is printed as an image in this scan and was read from it. The document states the method: 2.5-5 % of several emulsifier blends, blended to HLB values two units apart from 4 to 18, on 20 % or less of the material; liquids blended at room temperature, solids 10 C above their melting point; then four or five more emulsions one HLB unit apart to bracket the best range. It states that these figures supersede similar values published by ICI in other literature, and that surface-active materials such as fatty acids and fatty alcohols will likely require a higher HLB at high concentrations.

ICI Americas Inc., Wilmington, Delaware — The HLB System: a time-saving guide to emulsifier selection, "HLB values of blended ICI surfactants" (centre insert) · document dated 1984 · read 2026-09-30

The table prints eight SPAN/TWEEN and BRIJ pairs blended from 100/0 to 0/100 in steps of 5; the HLB of each emulsifier alone is its end column. The same document gives SPAN 80 as 4.3 and TWEEN 80 as 15.0 in its worked example (Chapter 5).

Common questions

Which emulsifiers does this cover?
The sixteen non-ionic emulsifiers of ICI’s blend table, in their families: sorbitan esters with polysorbates (SPAN and TWEEN), and laureth, ceteth, steareth and oleth pairs (BRIJ). Any other non-ionic can be entered by its HLB. Ionic emulsifiers have no HLB in this sense, so they cannot be blended by it.
Why is cetyl alcohol so high?
ICI gives the fatty alcohols a required HLB of 13 to 16, the highest in a typical oil phase, and warns that surface-active materials such as fatty acids and alcohols need higher still at high concentrations.
What if my oil is not listed?
The figure covers only the oils with a published value, and the page says how much of the phase that is. Put an unlisted oil in at its share and the page names it; a row of test emulsions finds its own figure.

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Goes well with

All tools
Lotions & creams Phases, q.s. to 100 %, usage rates, and the HLB your oils actually need
Oil & butter reference Saponification values, iodine, fatty acids — as published ranges with the source on every row

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