Cups to Grams Converter (Flour, Sugar, Butter, Water…)
A cup is a volume; a gram is a mass. They match only after you pick an ingredient density. This converter uses a US legal cup of 240 ml and typical packed-or-spooned kitchen densities — 125 g flour, 200 g sugar, 227 g butter, 240 g water, 185 g uncooked white rice, 245 g milk per cup. Approximate. A scale beats cups for baking.
Grams125
US cups (240 ml)1
Ounces (weight)4.41
Density used125 g/cup
How this calculation works
grams = cups × grams-per-cup for that ingredient. cups = grams ÷ grams-per-cup.
Densities are typical US-cup values, not laboratory assays. Scoop-and-level flour can swing 20% versus spooned flour.
Ounces shown are avoirdupois (grams ÷ 28.349523125), not fluid ounces.
Metric cups (250 ml) are about 4% larger than the 240 ml cup used here. Korean 종이컵 is not a US cup.
Worked example
2 cups all-purpose flour → 250 g. 400 g sugar → 2 cups. ½ cup butter → 113.5 g (one US stick is ½ cup / 113 g).
Grams per US cup used here
| Ingredient | g / cup (240 ml) |
|---|---|
| Water | 240 |
| All-purpose flour | 125 |
| Granulated sugar | 200 |
| Butter | 227 |
| Uncooked white rice | 185 |
| Milk | 245 |
Frequently asked questions
Why not weigh everything?
You should for pastry. Cups survive because many US recipes are written that way. Convert, then prefer a scale next bake.
Bread flour vs AP flour?
We use 125 g/cup AP-style. Bread flour is often similar; brown sugar packed is much heavier than 200 g.
Cooked rice?
No — uncooked rice density. Cooked rice holds water and is a different cup weight.
Salted vs unsalted butter?
Mass per cup is essentially the same. Salt is a flavor difference, not a volume one.
UK cup or Commonwealth cup?
This is 240 ml US. Some older UK recipes used 284 ml. When in doubt, weigh.
Are inputs stored?
No. Browser only.
This tool is provided for general information only. Verify important figures independently. · Last reviewed: August 25, 2026