Surfactant HLB Blend Calculator

Understanding the surfactant HLB blend calculator — concept and principle

The hydrophilic-lipophilic balance (HLB) is a number that describes how water-loving or oil-loving a nonionic surfactant is. Each oil needs a "required HLB" to be emulsified, usually reached by blending a high-HLB and a low-HLB surfactant. This calculator tells you what proportion of each to use.

The target splits the gap like a lever: the surfactant whose HLB is closer to 10 gets the bigger share.

How it is calculated

Blend HLB = w_A × HLB_A + w_B × HLB_B, with w_A + w_B = 1 (weight fractions).
Solving for the target: w_A = (HLB_target − HLB_B) ÷ (HLB_A − HLB_B).
w_B = (HLB_A − HLB_target) ÷ (HLB_A − HLB_B).

The results are percentages by weight of the total surfactant, not of the whole formulation.

The principle

William Griffin introduced the HLB scale in 1949 and, in 1954, defined it for many nonionic surfactants as 20 times the mass fraction of the hydrophilic part of the molecule, giving values from 0 (entirely oil-soluble) to 20 (entirely water-soluble). Because the scale is based on mass fractions, the HLB of a mixture is approximately the weight-weighted average of its components. Blending is therefore a lever rule: the closer the target is to one surfactant's HLB, the more of that surfactant you need.

Worked example

Defaults: HLB_A = 15 (a value typical of polysorbate 80), HLB_B = 4.3 (typical of sorbitan monooleate), target HLB = 10.
HLB_A − HLB_B = 15 − 4.3 = 10.7.
Fraction of A = (10 − 4.3) ÷ 10.7 = 5.7 ÷ 10.7 = 53.27%.
Fraction of B = (15 − 10) ÷ 10.7 = 5 ÷ 10.7 = 46.73%.
Check: 0.5327 × 15 + 0.4673 × 4.3 = 10.0.

Each point is the calculator re-run with only “HLB of surfactant A” changed; the gold point is the default example. Change the inputs above and this chart follows your numbers.

HLB of surfactant A	Fraction of A
3.75	-1,036.36%
7.5	178.13%
11.2	82.01%
15	53.27%
18.8	39.45%
22.5	31.32%
30	22.18%

How to read the result

Griffin's classic guide: HLB about 3 to 6 favours water-in-oil emulsions, about 7 to 9 wetting agents, about 8 to 18 oil-in-water emulsions, about 13 to 15 detergents and about 15 to 18 solubilisers. A target outside the range between your two surfactants gives a negative fraction, which means the pair cannot reach it. Test several blends around the calculated ratio, since required HLB values are estimates.

Common mistakes

Using the ratio for the whole formula; it describes only the surfactant portion.
Applying Griffin's mass-fraction scale to ionic surfactants, whose HLB values follow other methods and do not blend as linearly.
Ignoring temperature: nonionic ethoxylates become more lipophilic as temperature rises.

Keep in mind: HLB is a guide, not a guarantee of stability. Chemical type, oil polarity, electrolytes and processing all matter, so confirm with stability tests. Cosmetic and pharmaceutical products must also meet the applicable regulations.

Frequently asked questions

What is the required HLB of an oil?

It is the HLB at which a surfactant blend gives the most stable emulsion of that oil, determined experimentally and listed in supplier literature.

Can I blend three surfactants?

Yes, the blend HLB is still Σwᵢ × HLBᵢ, but there are infinitely many solutions, so fix one fraction first.

Why combine two surfactants rather than use one with the right HLB?

Pairs of high- and low-HLB emulsifiers often pack better at the oil-water interface and give more stable emulsions.

Sources: Griffin, W. C. (1949). Classification of surface-active agents by "HLB". Journal of the Society of Cosmetic Chemists, 1, 311–326. · Griffin, W. C. (1954). Calculation of HLB values of non-ionic surfactants. Journal of the Society of Cosmetic Chemists, 5, 249–256.

Checked 8 Nov 2026. Standard textbook formulas in SI units, computed in your browser. For learning and estimates — real designs must follow your local codes and be checked by a qualified engineer.

Your numbers