Liquids
Convert ounces of water to cups
One ounce of water weighs about 0.12 cup, and half a ounce comes to roughly 0.06 cup. Enter any amount below to convert it, or use the chart further down as a quick reference while you cook.
1 oz of water =
0.12 cup
About 1/8 cup in recipe notation
- ml
- 28.3
- tbsp
- 1.91
Water: 237 g per US cup · NIST Handbook 133. Water is the reference: 1 ml = 1 g. This is the only ingredient where volume and weight convert exactly.
Full water chart →Water at a glance
Every number on this page comes from a single figure: 237 grams per US cup (NIST Handbook 133).
- 1 cup
- 237 g
- 1 tablespoon
- 14.8 g
- 1 teaspoon
- 4.94 g
- 1 cup in ounces
- 8.36 oz
- 100 g in cups
- 0.422 cups
- Density
- 1.00 g/ml
ounces to cups chart for water
Print it, screenshot it, or bookmark this page — these are the amounts recipes ask for most often.
| Ounces (weight) | Cups (US) | Tablespoons (US) | Millilitres |
|---|---|---|---|
| 0.5 oz | 0.06 cup | 0.957 tbsp | 14.2 ml |
| 1 oz | 0.12 cup | 1.91 tbsp | 28.3 ml |
| 2 oz | 0.239 cup | 3.83 tbsp | 56.6 ml |
| 3 oz | 0.359 cup | 5.74 tbsp | 84.9 ml |
| 4 oz | 0.478 cup | 7.66 tbsp | 113 ml |
| 5 oz | 0.598 cup | 9.57 tbsp | 142 ml |
| 6 oz | 0.718 cup | 11.5 tbsp | 170 ml |
| 8 oz | 0.957 cup | 15.3 tbsp | 226 ml |
| 12 oz | 1.44 cup | 23 tbsp | 340 ml |
| 16 oz | 1.91 cup | 30.6 tbsp | 453 ml |
How this conversion is calculated
Volume-to-weight conversions are only as good as the density behind them. We treat water as 237 g per US customary cup, which works out to 1.002 g/ml. From there:
- Your ounces figure is converted into millilitres or grams using standard unit sizes (oz = 28.3 g).
- The density above bridges volume and weight in whichever direction you need.
- The result is rounded the way a cook would round it — to the nearest gram, or to a usable fraction such as 3/8 cups.
Measuring water accurately
Water is the reference: 1 ml = 1 g. This is the only ingredient where volume and weight convert exactly.
If a recipe matters to you — bread, macarons, anything with a tight hydration or ratio — weigh it. A £10 digital scale removes the single largest source of variation in home baking, and it is faster than washing three measuring cups.
When cups are fine
- Liquids measured in a proper jug, where volume is the honest unit anyway.
- Forgiving savoury cooking: soups, stews, stir-fries, marinades.
- Small amounts of leaveners and spices, as long as you use level spoons.
Frequently asked questions
How many cups are in 1 ounce of water?
1 ounce of water is 0.12 cup. This is based on a density of 237 g per US cup.
How many cups are in 2 ounces of water?
2 ounces of water is 0.239 cup, and 0.06 cup for half a ounce.
How much is 100 g of water in cups?
100 g of water is about 3/8 cups. Weight is always the more reliable measurement, so use a scale when the recipe gives grams.
Why do other sites give a different number for water?
Water is the reference: 1 ml = 1 g. This is the only ingredient where volume and weight convert exactly.
Do UK and Australian cups give the same result?
No. A US customary cup is 236.6 ml, a metric cup used in Australia and New Zealand is 250 ml, and an old UK imperial cup is 284 ml. Our default is the US cup, but you can pick metric cups in the converter.