Fresh Grapefruit Juice

One US cup of fresh grapefruit juice weighs 247 grams (8.7 ounces). Going the other way, 100 grams is about 0.40 cups.

Also called grapefruit juice, freshly squeezed grapefruit juice, pink grapefruit juice, white grapefruit juice, ruby red grapefruit juice, grapefruit juice raw.

Citrus juices compared: cup weights side by side, the source behind each, and why they differ.

Fruit juices compared: cup weights side by side, the source behind each, and why they differ.

Fresh grapefruit juice weighs 247 g per US cup (8.7 oz), a density of 1.044 g/mL, and pink and white grapefruit juice weigh the same. Three USDA records agree within 1 g per cup; with no independent laboratory measurement found yet, the figure is published at medium confidence.

Grapefruit juice here means juice squeezed from the fruit with nothing added. USDA keeps separate records for white and pink grapefruit juice, because the pink and red varieties carry pigments the white ones do not, but their composition is otherwise the same: about 90 g of water and 9.2 g of carbohydrate per 100 g. Pigment is a trace ingredient, so it changes the colour of the juice, not its weight.

USDA SR Legacy "Grapefruit juice, white, raw" (FDC 173039) publishes 1 cup = 247 g and 1 fluid ounce = 30.9 g, which agree with each other at 1.044 g/mL. "Grapefruit juice, pink, raw" (FDC 167774) publishes the same 247 g cup. USDA's survey database, FNDDS, lists "Grapefruit juice, 100%, freshly squeezed" (FDC 2709176) at 31 g per fluid ounce, which extrapolates to 248 g per cup; the 1 g gap is the rounding of a fluid-ounce figure to whole grams.

These are three USDA records rather than three independent measurements, which is why this entry stays at medium confidence. Retail labels cannot add an independent figure: bottled grapefruit juice, including Ocean Spray, states its serving in millilitres only. No laboratory density measurement for grapefruit juice turned up, unlike orange juice, which has two.

The physics still checks out. Grapefruit juice is slightly lighter per cup than orange juice (248 g) because it carries less dissolved sugar: US Customs laboratory methods give an average of 10.2 °Brix for unconcentrated grapefruit juice against 11.8 for orange. Less dissolved solid means a density closer to water, and 1.044 g/mL sits just where that difference predicts.

Practical guidance: for cocktails such as the Paloma and the Greyhound, for sorbets, dressings and grapefruit curd, 1 tablespoon is 15.4 g and 1/4 cup is 62 g, and a standard 1 1/2 oz bar pour is about 46 g. USDA's survey data puts the juice of one grapefruit at 196 g, roughly 4/5 of a cup, so a full cup usually takes one large or two small grapefruits.

King Arthur's ingredient weight chart has no grapefruit entry at all, so there is nothing to check against it. Among citrus juices, grapefruit sits between orange juice (248 g per cup) and lemon juice (244 g) and above lime juice (242 g); the citrus juice comparison page shows all four side by side.