Cups to Grams: Why Baking Needs a Scale

By Hutu Laurentiu

5 min read · Updated October 2026

"2 cups of flour" is not a measurement — it's a range. Depending on how you scoop, a cup of flour weighs 120-160 grams. That 30% spread is the difference between a tender cake and a brick. Here's why, and what to do about it.

The physics: cups measure space, grams measure stuff

A cup is 236.6 ml of volume. Grams measure mass. The bridge between them is density — and kitchen ingredients range from ~40 g/cup (puffed rice) to ~340 g/cup (honey). Flour is the worst case: scooping compacts it, sifting aerates it. Same cup, different flour mass. US "spoon and level" convention assumes ~125 g/cup for all-purpose flour; a heavy-handed scooper packs 150+.

The density table that saves recipes

• All-purpose flour: 1 cup ≈ 125 g (spoon & level)
• Bread flour: 1 cup ≈ 130 g · Cake flour: 1 cup ≈ 115 g
• Granulated sugar: 1 cup = 200 g (stable — sugar doesn't compact much)
• Brown sugar (packed): 1 cup ≈ 220 g
• Butter: 1 cup = 227 g (the label says it: 454 g sticks = 2 cups)
• Water/milk: 1 cup = 237 g ≈ 240 g (the only truly "1 cup = 240 g" cases)
• Chocolate chips: 1 cup ≈ 170 g · Chopped nuts: 1 cup ≈ 113 g

Notice: liquids and sugars convert reliably; anything powdery, flaky or chopped doesn't. That's the whole rule.

The UK/Europe problem, reversed

European recipes list grams; American ones list cups. Converting a US recipe for a European kitchen without a scale forces you to guess density. Best practical answer: buy a scale (10-15€, the single best baking upgrade). Second best: use the table above and accept ±10%. Worst: assume 1 cup = 240 g for everything — that ruins flour-based recipes instantly (240 vs 125 g is nearly double).

Sticky-ingredient tricks

Honey, syrup, peanut butter: oil the cup or spoon first — it releases clean. For butter, use the wrapper markings instead of a cup entirely. For small amounts (≤3 tbsp), teaspoons/tablespoons beat cups anyway: 1 tbsp = 15 ml ≈ 15 g water-weight, but again density decides — 1 tbsp honey is 21 g.

When cup conversion is safe

Soups, stews, sauces, smoothies — anything forgiving. Rice: 1 cup uncooked ≈ 185 g is consistent enough. Baking bread, cakes, macarons, pastry: weigh. Recipes that came from professional kitchens are written in grams because the authors got tired of the cup lottery.