Pearson's Square Calculator

Milk fat standardisation by blending two milks of different fat content to a target fat percentage.

Inputs

Higher-fat milk (e.g. cream)

% fat. Typical cream: 35–48%

Lower-fat milk (e.g. skim)

% fat. Skim: 0.05–0.5%

Target fat content

% fat. UK whole milk: 3.5–4.0%

Total volume needed (optional)

Litres or kg. Used to calculate actual quantities.

Parts higher-fat milk—

Parts lower-fat milk—

Higher-fat quantity—

Lower-fat quantity—

Enter the three fat percentages to calculate the blend.

The Pearson's Square

Higher fat40

↘

Parts low—

↙

Target3.5

↗

Lower fat0.1

↖

Parts high—

Higher-fat ratio	—
Lower-fat ratio	—
Total parts	—
Verification (calculated fat %)	—

Method: Subtract diagonally. The differences on the opposite corners are the blend parts. (Target − Lower) gives parts of the higher-fat milk; (Higher − Target) gives parts of the lower-fat milk.