A cup of milk in grams, and why it beats water
Whole milk weighs 244 grams to the US cup. Most charts print a rounder 227, borrowed from a rule about water, and milk is heavier than water. The gap is small on one cup and real across a custard, so it is worth knowing where the number comes from.
Why a cup of milk is not eight ounces
A cup of water weighs close to 8 ounces, because a US cup is 236.6 millilitres and a millilitre of water is almost exactly a gram. That coincidence hardened into a rule, and the rule got pinned to every liquid poured into a cup. Milk breaks it. Milk carries dissolved sugar and protein, so a given volume weighs more than the same volume of water.
| Authority | A US cup of whole milk |
|---|---|
| King Arthur Baking ingredient weight chart | 227 g |
| USDA FoodData Central | 244 g |
King Arthur's 227 grams is what 8 avoirdupois ounces round to, the eight-ounce rule applied to milk as if it were water. The USDA put whole milk on a scale and read 244. We publish 244, and the reason we side with the measurement over the rounding sits on the methodology page. The imperial fluid ounce that starts this confusion is on UK imperial measurements.
The Japanese tables make the same mistake, and one corrects it
Japan's standard tables show the split from the other side. One reference gives milk its own row and weighs it heavier than water; another folds milk into the water row and calls them equal, the same shortcut King Arthur takes.
| Japanese source | Milk, 200 ml cup |
|---|---|
| Benricho measuring cup and spoon weight table | 210 g |
| Kyoritsu Foods, weight table for the standard measuring cup and spoons | 200 g |
Water is 200 grams for that same 200 millilitre cup, so the row that reads 210 is saying milk runs about five percent heavier than water, and the row that reads 200 is repeating the water rule. Two authorities, one measuring milk and one assuming it, exactly the disagreement the US charts have.
Milk conversions in full
| Whole milk | Grams | Millilitres |
|---|---|---|
| 1 tablespoon | 15.3 g | 14.8 ml |
| 1/4 cup | 61 g | 59.1 ml |
| 1/2 cup | 122 g | 118.3 ml |
| 3/4 cup | 183 g | 177.4 ml |
| 1 cup | 244 g | 236.6 ml |
| 2 cups | 488 g | 473.2 ml |
Density used: 1.03 g per ml, heavier than water's 1.00. A metric 250 ml cup of milk is 250 g.
Whole, skim, and the fat that barely moves the weight
Our 244 grams is whole milk, and switching to skim or two percent changes the cup by under two percent, less than the gap between the two US authorities above. Fat is lighter than water, so whole milk with more fat is a touch less dense than skim, but the shift is small enough that a recipe cannot tell. The number that matters is that milk of any fat runs heavier than water, so none of them is the 227 grams the eight-ounce rule would hand you. When a recipe says milk without a fat level, whole is the safe read, and the 244 gram cup covers it.
Questions about milk weight
- How many grams is a cup of milk?
- 244 g for whole milk, measured by the USDA. King Arthur prints 227, which is exactly 8 ounces, but milk is denser than water and weighs more than the eight-ounce rule predicts. We publish 244.
- Why do some charts say 227 grams and others 244?
- 227 grams is 8 avoirdupois ounces, the old rule that a cup of liquid weighs half a pound. It holds for water and not for milk, which the USDA weighed at 244.
- Can I measure a heaped tablespoon of milk?
- No. A liquid has no heap: it fills the spoon level and the weight follows the volume. One tablespoon of milk is about 15 grams, and there is no larger heaped figure.
Sources
USDA FoodData Central SR Legacy for the 244 gram cup and the 15 gram tablespoon, King Arthur Baking for the 227 gram cup. The Kagawa Nutrition University standard tables, as reproduced by Benricho and Kyoritsu, for the two Japanese figures. Sanitarium for the metric cup, and Roskachestvo for the rule that liquids carry no heap. Full citations on the sources page.