Why the ingredient matters
Volume and weight are not interchangeable
Cups measure volume, while grams measure mass. The same cup can hold light, airy oats or dense honey, so there is no single cups-to-grams factor that works for every recipe. This converter applies the selected ingredient's working weight instead.
To go from grams back to cups, divide the gram amount by the ingredient's grams-per-cup value. The calculator keeps the side you entered fixed when you switch ingredients.
Reference assumptions
Weights used by this calculator
Each value below is a practical recipe estimate for one level 240 mL US legal cup. The density is derived from that working weight so you can see exactly what the calculation assumes.
| Ingredient | Grams / cup | g / mL | How it is measured |
|---|---|---|---|
| All-purpose flour | 120 g | 0.500 | Spooned into the cup and leveled; not sifted or packed. |
| Granulated sugar | 200 g | 0.833 | A level cup of standard white granulated sugar. |
| Brown sugar (packed) | 213 g | 0.887 | Pressed firmly into the cup, then leveled. |
| Butter | 227 g | 0.946 | Solid butter filling a level cup; approximately two US sticks. |
| Rolled oats | 90 g | 0.375 | A level cup of dry old-fashioned rolled oats; not compacted. |
| Honey | 340 g | 1.417 | Room-temperature liquid honey, with the cup filled level. |
| Water | 240 g | 1.000 | Kitchen-temperature water, treated as 1 gram per milliliter. |
Brand, humidity, grind, temperature, scooping, and packing can all change an ingredient's weight. For precision baking, use a scale and follow the gram amount supplied by the recipe or ingredient manufacturer when one is available.
Cup definition
This tool uses a 240 mL US legal cup
The US legal cup used for nutrition labeling is exactly 240 mL. A US customary cup is approximately 236.588 mL, and metric cups can be 250 mL. Check the recipe's origin when that difference could matter.
Need a volume-only calculation? Use the cups to milliliters converter.
Sources and method
How the reference values were chosen
- FDA household-measure guidance defines one cup as 240 mL for US nutrition labeling.
- King Arthur Baking's ingredient weight chart provides practical volume-to-weight benchmarks for common baking ingredients.
The calculator turns those references into rounded working estimates for a 240 mL cup. If a recipe, package, or manufacturer supplies its own gram amount, use that source-specific value—it takes precedence over this general table.
Common questions
Cups and grams in the kitchen
How many grams are in one cup?
It depends on the ingredient. In this calculator, one 240 mL cup is 120 g for spooned-and-leveled all-purpose flour, 200 g for granulated sugar, and 240 g for water.
Should flour be scooped or spooned?
This tool assumes flour is spooned into the measuring cup and leveled. Scooping directly from a container can compact flour and produce a heavier cup.
Can I convert grams back to cups?
Yes. Enter a value in the grams field and the calculator will divide it by the selected ingredient's working grams per cup.