- Why isn't 1 cup = a fixed number of grams?
- Because a cup measures volume (236.6 mL in the US) and grams measure mass. The conversion depends on the ingredient's density. A cup of flour weighs about 125 g, a cup of sugar weighs about 200 g, a cup of honey weighs about 340 g — same cup, almost triple the weight. That's why bakers reach for a scale: grams are unambiguous, cups depend on what you're scooping.
- Why does flour have four entries?
- Because not all flour is the same density. All-purpose: 125 g/cup. Bread flour: 130 g/cup (slightly denser, more protein). Cake flour: 113 g/cup (finer, lighter). Whole wheat: 120 g/cup. The differences are small per cup but add up across a recipe — a four-cup loaf can vary by 70 g depending on which flour you use.
- How accurate is 'one cup of flour'?
- Honestly? Not very. The same person scooping flour from the same bag can produce cups that weigh anywhere from 120 g to 150 g — a 25% spread — depending on whether they scoop, spoon, sift, or pack. The standard convention is 125 g/cup using the spoon-and-sweep method (spoon flour into the cup, then level it off with a knife). That's why professional bakers weigh: a 1% error in flour is undetectable; a 20% error makes a different recipe.
- Why is brown sugar measured packed?
- Because brown sugar has irregular crystals coated in molasses, and unpacked it traps a lot of air. 'Packed' means pressing it firmly into the cup so it holds the cup's shape when you turn it out. A packed cup of brown sugar weighs ~220 g — about 10% more than an unpacked cup. Every recipe assumes packed unless it says otherwise.
- Is a US cup different from a metric cup?
- Yes. US cup: 236.588 mL. Metric cup (used in Australia, Canada, the UK in modern recipes): 250 mL. The difference is about 6% — usually not enough to ruin a recipe but enough to matter for precise baking. This calculator uses the US cup. For metric-cup recipes, multiply the cups by 1.057 to get US cups, or convert to grams directly and ignore the cup conversion.
- What's the conversion to ounces?
- 1 ounce = 28.35 g. The widget shows grams and ounces together for each result. Note that 'fluid ounces' (a volume) and 'ounces' (a weight) are different units that happen to share a name — a cup of water is 8 fluid ounces (volume) AND ~8.4 ounces (weight, by coincidence), but a cup of flour is 8 fluid ounces (volume) but only ~4.4 ounces (weight).
- Why don't recipes just use grams?
- American home recipes still use volume measurements for historical reasons — measuring cups have been standard kitchen equipment for a century, scales much more recently. Europe and most of the rest of the world have used scales for baking for decades. The trend in serious American baking books (Stella Parks' BraveTart, Claire Saffitz's books, ATK) is to publish both, with grams primary.
- Is my input saved or sent anywhere?
- No. The conversion runs entirely in your browser. Nothing is sent to a server, logged, or stored.
