How to Use AquaMath

Select Product Type & Target pH

Choose the product type that matches your formula goal. AquaMath pre-fills the typical pH range for that type. Adjust the target pH if needed — pH directly affects preservative selection, active ingredient stability, and gel formation (Carbomer neutralizes above pH 5.5).

Add Water-Phase Actives

These are water-soluble ingredients with specific skin benefits — Niacinamide, Allantoin, Panthenol, Sodium Hyaluronate, Alpha Arbutin, Vitamin C, Peptides. Each has a suggested usage range. Most are heat-stable up to 140°F (60°C), but check each ingredient's datasheet.

Add Humectants

Humectants draw moisture to the skin from the environment and deeper skin layers. Glycerin (5–10%) is the most common. Propylene Glycol, Sodium PCA, and Betaine are alternatives. Keep total humectants at or below 15% — above that, formulas can feel sticky and may interfere with thickeners.

Add Thickeners (if needed)

Carbomer (0.3–1%) makes gels but is electrolyte-sensitive. Hydroxyethylcellulose (0.5–2%) is more salt-tolerant. Sodium Hyaluronate at higher concentrations (0.1–0.5%) adds viscosity without building a gel. Xanthan Gum (0.2–0.5%) works in light tonics. Thickener is optional for thin sprays and mists.

Add Oil Phase (up to 5%)

Optional oils, esters, and silicones add slip, emolliency, or a light skin feel. Total oil phase must stay at or below 5% to remain solubilizable. Oil-soluble antioxidants (Tocopherol, Rosemary Oleoresin, BHT, Ascorbyl Palmitate) also count toward this total. Above 5%, the formula needs a full emulsifier — use LotionMath.

Add Solubilizer

AquaMath auto-calculates the required solubilizer amount based on total oils + antioxidants + fragrance, using each solubilizer's typical ratio. You can override this amount. If using Polysorbate 20, the ratio is 3:1 (3 parts Polysorbate per 1 part oil). Add slightly more if your formula is hazing on cold storage.

Add Preservative

Select a preservative that matches your target pH. AquaMath flags mismatches: Sodium Benzoate becomes ineffective above pH 5, Potassium Sorbate above pH 6. Phenoxyethanol blends (Optiphen, Optiphen Plus, Euxyl PE 9010) and Germall Plus work well across a wider pH range.

Set Fragrance & IFRA Category

Select the body part / use type to see the suggested IFRA category and usage rate. AquaMath auto-suggests a category based on your product type (e.g., serums → Cat 5B, body mists → Cat 2). Enter your fragrance percentage — the badge shows the suggested range. If you exceed the category maximum, a warning appears. For precise compliance, use IFRAMath with your specific blend.

Adjust pH Adjuster and Review Warnings

Add an acid (Citric Acid, Lactic Acid) or base (Sodium Hydroxide, Sodium Bicarbonate) to reach your target pH. Review all warnings in the results panel before finalizing your formula. The results show water percentage, full ingredient list, INCI order, and all detected issues.

Set pH Before Choosing the Preservative

Your pH target determines which preservatives will work. Set it first based on the product type, skin-active stability windows, and Carbomer requirements — then pick the preservative that matches.

Solubilize Everything Oil-Soluble

Fragrance, carrier oils, esters, silicones, and all oil-soluble antioxidants need a solubilizer. AquaMath counts all of them in the auto-calc. If your formula is still hazing, increase the solubilizer slightly or reduce total oil-phase inputs.

Keep Humectants in Balance

Glycerin above 10% starts to feel tacky. Blending two or three humectants at lower levels (e.g., 5% Glycerin + 3% Sodium PCA + 2% Betaine) is more elegant than maxing out a single one.

Use a Chelator for Hard Water

Tetrasodium EDTA or Disodium EDTA at 0.05–0.1% sequesters trace metals that can discolor formulas, deactivate preservatives, and destabilize emulsifiers. Worth adding to any formula with tap water or botanical extracts.