How does human breast milk density compare to cow's milk?

Human mature breast milk (approximately 1.04 g/ml) is slightly denser than cow's whole milk (1.030–1.035 g/ml). The difference is small—less than 3 g per cup—and reflects the distinct fatty acid and lactose composition. Both are heavier than water by volume.

When would this volume-to-gram conversion be useful?

This conversion is relevant for infant feeding measurement when accurately converting expressed breast milk from volume (ml or oz) to weight (grams), for clinical nutrition calculations in neonatal care, and for food science or lactation research contexts. It is not a cooking or culinary ingredient.

Milk, Human, Mature, Fluid (For Reference Only)

By Fidamen-Chefsolver Team | Reviewed by Ugo Candido

Human mature breast milk is included in the USDA nutritional database as a reference entry with a density of approximately 1.04 g/ml—comparable to cow's whole milk (1.030–1.035 g/ml) and slightly denser due to its unique fat globule composition and lactose profile. The "(For Reference Only)" designation in the original USDA data reflects that this is not a commercial food ingredient. This conversion page is intended for infant feeding measurement (precisely measuring expressed breast milk for bottle feeding), lactation tracking, neonatal clinical nutrition, and food science reference. A cup of human mature breast milk weighs approximately 246 g; a tablespoon weighs approximately 15.4 g.

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Ingredient

→

US cup = 236.588 mL
1 tbsp = 14.787 mL
1 tsp = 4.929 mL

Reference table

Milk, Human, Mature, Fluid (For Reference Only) — milliliters to grams
mL	g
10	10
25	26
50	52
75	78
100	104

Primary use case: measuring expressed breast milk for infant feeding by volume-to-weight conversion. Also referenced in clinical nutrition and lactation research. Not a cooking or baking ingredient.

How this conversion works

Milliliters measure volume while grams measure weight. Because Milk, Human, Mature, Fluid (For Reference Only) has a density of 1.04 g/mL, 10 mL weighs 10 g — not 10 g as it would for water. This converter uses the real density of Milk, Human, Mature, Fluid (For Reference Only) so every measurement is accurate.

Measurement notes

Values are rounded to the nearest whole gram. Actual weight can vary slightly with compaction, temperature, and brand. For precision baking, a kitchen scale is always more reliable than volume measurements.

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FAQ

How does human breast milk density compare to cow's milk?: Human mature breast milk (approximately 1.04 g/ml) is slightly denser than cow's whole milk (1.030–1.035 g/ml). The difference is small—less than 3 g per cup—and reflects the distinct fatty acid and lactose composition. Both are heavier than water by volume.
When would this volume-to-gram conversion be useful?: This conversion is relevant for infant feeding measurement when accurately converting expressed breast milk from volume (ml or oz) to weight (grams), for clinical nutrition calculations in neonatal care, and for food science or lactation research contexts. It is not a cooking or culinary ingredient.