Cream Fat Content Calculator

These are legal minimum milk-fat percentages under the UK Compositional Standards for Cream (Dairy UK / PTF): half cream 12%, single cream 18%, sterilised cream 23%, whipping cream 35% (commonly sold at 35-36%), double cream 48% and clotted cream 55%. Half-fat creme fraiche is about 15% and full-fat creme fraiche about 30%. This calculator uses 36% as a representative value for whipping cream — pick Custom if your carton states a different figure.

You might mix creams if you need a specific fat content that is not sold as a standard product, or if you only have two types and need something in between. For example, mixing double and single cream can approximate whipping cream if you have run out.

You need roughly 35% fat to whip cream into stable peaks; the calculator uses a conservative 30% default threshold you can adjust under Advanced Options. Below about 30% the fat globules cannot trap enough air to hold structure. Double cream (48%) whips very stiffly, whipping cream (around 35-36%) gives softer peaks, and single cream (18%) will not whip at all.

The fat content determines how a cream behaves when heated. Higher-fat creams are more stable and less likely to curdle or split when added to hot sauces. Single cream (18%) can curdle if boiled, while double cream (48%) is very heat-stable.

The calculator blends the two creams by volume using a weighted average (the same idea as Pearson’s square). Fat content is legally defined by weight (m/m), and cream densities vary slightly with fat — single cream is about 1.01 g/ml and double cream about 0.99 g/ml. Because of that small density difference, a strict mass balance differs from this volume result by under one percentage point, which is well within practical kitchen tolerance. For exact dairy standardisation, weigh the creams instead of measuring by volume.