1 cup water = 236.59 grams
Volume is only half the story. Water weighs 236.588 g per US cup (reference), so we convert with a tested, ingredient-specific factor instead of a generic table.
Water cups to grams
Reference · rounded for kitchen use
| Cups | Grams | Ounces |
|---|---|---|
| ¼ cup | 59.15 g | 2.086 oz |
| ⅓ cup | 78.85 g | 2.782 oz |
| ½ cup | 118.29 g | 4.173 oz |
| ⅔ cup | 157.73 g | 5.564 oz |
| ¾ cup | 177.44 g | 6.259 oz |
| 1 cup | 236.59 g | 8.345 oz |
| 1 ½ cups | 354.88 g | 12.52 oz |
| 2 cups | 473.18 g | 16.69 oz |
| 3 cups | 709.76 g | 25.04 oz |
Exact factor details
- Exact factor
- 1 cup = 236.588 g (reference)
- Significant digits
- 3 significant figures for table display
- Data source
- Exact by definition (1 US cup = 236.588 ml)
Why water conversions vary
Water is the reference point for volume-to-weight conversion: one US cup is 236.588 ml by definition, and water's density makes that essentially 236.6 g at kitchen temperatures. The tidy 250 g figure belongs to the metric cup, not the US cup. This exact relationship is why water is used to calibrate measuring equipment.
Our factor for water — 236.588 g per US cup — comes from Exact by definition (1 US cup = 236.588 ml). Weighing beats measuring cups for repeatability: a scale gives the same result every time regardless of how the ingredient settled, and it scales recipes cleanly. Note that a US cup (236.6 ml) and a metric cup (250 ml) are not the same; recipes from outside North America may assume the metric size, which shifts every weight by about five percent.
The table below lists the amounts bakers actually reach for — quarters, thirds, and halves of a cup through three full cups — computed directly from the factor above. The converter handles any other amount instantly and uses the exact same number, so the quick reference and the live result can never drift apart.
Frequently asked questions
How much does 1 cup of water weigh?
One US cup of water weighs 236.588 g (reference). This comes from Exact by definition (1 US cup = 236.588 ml).
Why do some recipes list a different weight for water?
Measuring conventions and brands differ, and packing changes the weight. We state our convention openly; when a recipe names its own gram value, follow that one for best results.
Should I measure water by cups or by weight?
Weight, whenever the recipe allows. 1 US cup of water = 236.6 g ≈ 237 ml; the 250 ml figure is a metric cup, not a US one.