Water cups to grams converter
Water is the reference for kitchen measures: one millilitre weighs about one gram. Use this to find the weight of water in any cup or spoon.
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How to use it
- Enter amount, measure and density.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Grams = volume in mL × 0.9982 g/mL, the density of pure water at 20 °C. One US cup is exactly 236.5882365 mL, so it weighs about 236.2 g.
Example
Inputs: Amount = 1, Measure = US cup (236.6 mL), Density = 0.9982 g/mL. Result: Weight in grams: 236.2 g; Weight in ounces: 8.33 oz; Volume in millilitres: 236.6 mL.
Limits and caveats
- Water density changes slightly with temperature: 1.000 at 4 °C and 0.958 near boiling.
- Mineral content in tap water makes a negligible difference for cooking.
Questions about this tool
How many grams is a cup of water?
A US cup weighs about 236 g, and a 250 mL metric cup about 250 g in practice.
Is a litre of water exactly one kilogram?
Very close: 1000 g at 4 °C and about 998 g at room temperature.
When should I use a density of 1?
For most recipes treating 1 mL as 1 g is fine, so set the density to 1 for round numbers.