HLB Calculator for Emulsifiers

How It Works

The HLB (Hydrophilic-Lipophilic Balance) system, developed by William Griffin in 1949, assigns a number from 0-20 to surfactants based on their water-loving vs. oil-loving character. This number predicts which type of emulsion a surfactant will form and how stable it will be.

The key insight: every oil phase has a "required HLB" — the ideal emulsifier HLB value that produces the most stable emulsion with that oil. By blending a high-HLB emulsifier with a low-HLB one, you can hit any target HLB value precisely.

The Formulas

Weighted required HLB (for oil blends):

Required HLB = (Oil₁ HLB × Oil₁%) + (Oil₂ HLB × Oil₂%) + ... ÷ Total%

Mixed emulsifier HLB:

Mixed HLB = (Emulsifier A HLB × %A + Emulsifier B HLB × %B) ÷ 100

Reverse calculation (find ratio for target):

%A = (Target HLB - HLB_B) ÷ (HLB_A - HLB_B) × 100

HLB Ranges and Applications

| HLB Range | Application | |-----------|------------| | 1-3 | Anti-foaming agents | | 3-6 | W/O emulsions (cold creams) | | 7-9 | Wetting agents | | 8-16 | O/W emulsions (lotions, creams) | | 13-16 | Detergents | | 16-18 | Solubilizers |

How to Use This Calculator

This calculator has three connected sections:

Section 1 — Find Your Target:

1. Add your oil phase components and their percentages
2. The calculator shows the weighted required HLB
3. Click "Use as Target" to send this value to Section 3

Section 2 — Check a Blend:

1. Select two emulsifiers you have on hand
2. Adjust the ratio slider
3. See if the resulting HLB matches your target

Section 3 — Get the Recipe:

1. Enter your target HLB (or auto-fill from Section 1)
2. Select one high-HLB and one low-HLB emulsifier
3. Get the exact percentage of each needed

Tips & Safety Notes

• The HLB system is a starting point, not gospel. Always stability-test your formulations at room temperature and at 40°C for 4-8 weeks
• Total emulsifier amount is separate from ratio. Most O/W lotions use 3-8% total emulsifier by weight of the entire formulation. This calculator tells you the ratio between emulsifiers, not the total amount
• Temperature sensitivity: Some emulsifiers (like Polysorbate 80) perform differently above their cloud point. Factor in your processing temperature
• Co-emulsifiers like cetyl alcohol or stearic acid can shift effective HLB. If your formula includes these in the oil phase, account for their contribution
• pH sensitivity: Some emulsifiers (especially anionic ones) require specific pH ranges. Check compatibility before combining

Related Tools

• Lye & Water Calculator — for soap makers transitioning into lotion formulation
• Soap INS Predictor — another oil-data-driven calculator using the same raw materials

FAQ

Why do I need two emulsifiers instead of one?

A single emulsifier rarely matches your oil phase's exact required HLB. Blending a high-HLB and low-HLB emulsifier lets you hit any target precisely. Research also shows that blends often produce more stable emulsions than single emulsifiers at the same HLB.

What if my oil isn't in the database?

You can estimate based on similar oils. Most vegetable carrier oils (olive, sweet almond, jojoba) have required HLB values between 6-8. Mineral oil is higher at 10-12. For critical formulations, determine the required HLB experimentally by making test batches with emulsifier blends at different HLB values.

How accurate is the HLB system?

The HLB system is a useful approximation that gets you in the right neighborhood. Real-world stability depends on additional factors: electrolyte concentration, pH, temperature, and mechanical processing. Use HLB to narrow your starting formula, then optimize through bench testing.

Can the target HLB be different from what the calculator suggests?

Yes. Published required HLB values are averages. Your specific oil blend, water phase ingredients, and processing method may work better at slightly different values (±1-2 HLB units). If your first attempt separates, try adjusting the target by 1 unit in either direction.

Last reviewed: June 2026