237 g of water is 1 cup. Water is the reference for every volume-to-weight conversion in the kitchen: one US cup holds 236.6 millilitres, and one millilitre of water weighs one gram, so the numbers line up almost exactly. Every other ingredient is measured against water, which is why this page exists even though nobody needs a conversion chart to measure water.
All figures on this page are approximate, and they come from USDA, measured poured. When a recipe has to work the first time, verify with a kitchen scale.
Putting the numbers to work
A bread dough with a precise hydration
A bread recipe calls for 355 g of water, which is 1 1/2 cups, for 500 g of flour. That is a 71 percent hydration dough, which makes a soft, open crumb. Weighing the water is the most accurate way to control hydration, because a jug measurement can be off by 10 g, which changes the dough noticeably.
A stock pot for a Sunday soup
A soup recipe uses 1,422 g of water, which is 6 cups, as the base for a vegetable stock. At this scale, a jug is the practical tool, and the exact grams barely matter: a cup more or less changes the soup slightly, but it is still soup. Use the jug, not the scale, for large volumes of water.
A rice recipe that depends on the water ratio
A rice recipe uses 474 g of water, which is 2 cups, for 1 cup of rice. The water-to-rice ratio is the whole recipe, and it is why rice cookers work: they measure the water precisely and cook until it is absorbed. Measure the water in a jug, but check the level at eye level.
The numbers in a table
| Cups | Grams of water |
|---|---|
| 1/4 cup | 59.2 g |
| 1/3 cup | 79 g |
| 1/2 cup | 118.5 g |
| 2/3 cup | 158 g |
| 3/4 cup | 177.8 g |
| 1 cup | 237 g |
| 1 1/2 cups | 355.5 g |
| 2 cups | 474 g |
| 3 cups | 711 g |
| 4 cups | 948 g |
Quick reference: 100 g of water is about 0.42 cups, and 50 g is about 0.21 cups. All figures are approximate; verify with a kitchen scale when it matters.
Tips for best results
Pour liquids at eye level and read the meniscus, not the top of the curve, against the jug markings. Cold liquids are slightly denser than warm ones, but the difference is a gram or two per cup and will not change a recipe. If your jug only has millilitres, remember one US cup is 236.6 ml, so a recipe asking for 118.5 g of water is asking for roughly half a cup, or about 118 ml. Never measure a liquid in a dry measuring cup: the flat top makes it impossible to fill to the line without spilling, and you will consistently under-measure. A clear jug with a spout is the right tool, and it costs less than a single ruined cake.
Scaling is straightforward once you know the cup weight. Doubling a recipe that calls for 237 g of water means measuring 474 g, or 2 cups, and tripling it means 711 g, or 3 cups. Halving is just as easy: half a cup is 118.5 g. The key is to scale every ingredient by the same factor, because changing one ingredient without changing the others throws the recipe out of balance. A cake scaled by half still needs half the flour, half the sugar, half the butter and half the water, not just half of one of them. If you are scaling a recipe by an awkward factor, like two thirds, weigh the water rather than trying to measure two thirds of a cup in a jug, because the jug markings are not precise enough for fractions of a cup.
When should you weigh water instead of measuring it? Whenever the recipe has to work the first time, and whenever the amount is large. A kitchen scale costs less than a single failed cake, and it removes the biggest source of variation in home cooking: the way ingredients pack into a cup or a spoon. Put the bowl on the scale, press tare, and add the water until the display shows the number you need. There is nothing to wash afterwards except the bowl, and the result is the same every time. For small amounts, a level spoon is accurate enough, and for liquids, a jug is fine, but for anything where precision matters, the scale is the tool to reach for.
Storage. No special storage needed.
- One US cup is 236.6 ml, so water is 237 g per cup.
- Weigh water for bread doughs; use a jug for soups.
- Read a jug at eye level, not from above.
How the measurement works
The figure on this page comes from USDA, measured poured. The reference liquid for all volume-to-weight conversion. Every kind of cooking, baking and drinks.
A note on disputed figures. One US cup is 236.6 ml, so water weighs 237 g. King Arthur rounds water to 227 g; we use the exact 237 g.
All results on this page are approximate. Ingredient weights vary with brand, humidity, temperature and how firmly you pack the cup, so when a recipe has to work the first time, weigh the ingredient on a kitchen scale and use the numbers here as a guide.
Frequently asked questions
Why is a cup of water 237 g and not 240 g?
A US cup holds 236.6 millilitres, and one millilitre of water weighs one gram, so a cup of water is 236.6 g, rounded to 237 g. Some charts round it to 227 g, which is 8 ounces by weight, but 237 g is the accurate figure.
Is a cup of water the same as a cup of milk?
No. A cup of milk is 244 g, because milk contains fat, protein and lactose dissolved in the water. The difference is 7 g, which is small but real, and it matters in recipes where the liquid quantity is precise.
Does hot water weigh less than cold water?
Very slightly. Warm water expands, so a cup of hot water weighs a gram or two less than a cup of cold water. The difference is too small to affect any recipe, so measure water at whatever temperature it happens to be.
How many cups is a litre of water?
A litre of water is 1,000 g, which is about 4.23 cups. A litre is a metric measure and a cup is an American one, so the conversion is not a round number, but 4 cups plus 3 tablespoons is close enough for cooking.
Should I weigh water or measure it in a jug?
For small amounts in baking, weigh it: a scale is more accurate than a jug. For large amounts like soup stock, use a jug, because weighing litres of water is impractical and the exact amount does not matter.
Keeping a conversion note in the kitchen: if you cook from American recipes often, write the gram weights of the ingredients you use most on a card and stick it inside a cupboard door. A short list covering flour, sugar, butter, milk and oil will handle most recipes, and it saves you looking up the same number every time. Update the card when you buy a new ingredient, and note the method next to the weight, because a number without a method is only half a conversion.