A kilogram of water fills roughly 4.22 US cups. If you have just bought a 1 kg bag or tub and your recipe is written in cups, that is the conversion you need: divide 1,000 g by the weight of one cup, 237 g poured (USDA), and the answer is 4.22 cups. Treat it as a close, practical figure rather than an exact one, and weigh the ingredient whenever precision matters.

Water is the reference liquid for all volume-to-weight conversion. It is used for every kind of cooking, baking and drinks. That is why the kilogram-to-cups question comes up so often: water is sold by weight in most countries, while many recipes — especially American ones — measure it in cups. This page converts the whole kilogram, not just a single cup, so you can plan a whole bag or tub against a recipe instead of converting one spoonful at a time.

Conversion table: kilograms of water to cups

One US cup is 236.6 ml, and one cup of water weighs 237 g poured. Every row below is that cup weight divided into the weight shown, so the whole table follows from a single number. Figures are rounded to two decimal places and labelled approximate.

Weight Cups (approx.)
100 g 0.42
250 g 1.05
500 g 2.11
750 g 3.16
1 kg (1,000 g) 4.22
1.5 kg (1,500 g) 6.33
2 kg (2,000 g) 8.44

The same cup weight works in the other direction too:

Measure Weight (approx.)
1 cup 237 g
1 tablespoon 14.8 g
1 teaspoon 4.94 g
1 kg in tablespoons about 68 tbsp

If you only need part of the kilogram, the table above is the fastest way to read it off. Half a kilogram is 2.11 cups, a quarter is 1.05 cups, and 100 g — a common recipe amount — is 0.42 cups.

How the figure is worked out

The calculation is a single division: 1,000 g ÷ 237 g per cup = 4.22 cups. The only input is the weight of one cup of water, and that comes from USDA, which lists one US cup of water at 237 g, poured. The confidence rating on that figure is high, which means it is a published, checked value rather than an estimate — but it is still a cup measurement, and cups are never as exact as grams.

One thing to know before you use the number: 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.

Poured means filling the cup from a jug and reading the level at eye height, with the cup on a flat surface. Liquids do not pack or settle the way dry ingredients do, so the main error is a meniscus read at an angle or a cup that is not quite level.

That is also why every number here carries the word approximate. A cup is a volume measure being used as a stand-in for weight, and the two only line up when the filling method matches the published one. If the dish is forgiving — a stew, a marinade, a crumble topping — the cup figure is plenty. If it is a cake, a loaf of bread, or anything where a 10% error changes the texture, weigh the ingredient on a kitchen scale and skip the cups entirely.

Worked examples

The table is useful, but recipes do not come in kilograms. Here are three ordinary situations where the kilogram-to-cups figure does real work.

Example 1 — a large batch of drinks

A punch or infused-drink recipe calls for 2 cups of water, which weigh 474 g. A 1 kg bottle or carton holds 4.22 cups, so one bottle covers the recipe and leaves 2.22 cups — roughly another small jug. Because liquids pour evenly, this is one of the most reliable cup conversions on the site; the only real error is misreading the jug.

Example 2 — a marinade scaled up

A marinade uses ¼ cup of water (59.2 g) for a kilo of meat. Doubling the meat doubles the marinade to ½ cup, 118.5 g. A 1 kg bottle of water would make about 8 such doubled marinades, which is a handy way to judge whether the bottle in the cupboard will last the barbecue season.

Example 3 — baking with a liquid measure

A cake recipe lists 100 ml of water rather than grams or cups. One hundred millilitres is about 0.42 cups, and at 237 g per cup that is roughly 1 g — near enough to 100 g that many cooks treat millilitres and grams as interchangeable for thin liquids. For water that shortcut is reasonable, but check the density note in the method section before relying on it for thicker liquids.

Measuring it well, and storing what is left

Liquids are the easiest ingredient to measure in cups, and the mistakes are small ones. Read the jug at eye level on a flat surface, not held up in the air, and check the meniscus — the bottom of the curve, not the top edge where it climbs the glass. A second, less obvious mistake is swapping water for water cup-for-cup in a recipe that depends on its acidity, sugar, or flavour: the volume is the same, but the recipe is not.

Storage matters once you have opened a kilogram pack. No special storage needed. A kilogram is a lot of water for a home kitchen — for most households it will last weeks or months — so decanting it into a sealed container on the day you open it is worth doing: it keeps the weight stable, keeps moisture out, and means the cup you measure in a month weighs the same as the cup you measure today.

Without a scale, tablespoons are the fallback: one kilogram of water is about 68 level tablespoons, and one cup is 16 tablespoons, so you can build any amount in the table above from spoonfuls. It is slower than weighing, and each spoonful adds its own small error, but for soups, marinades, and everyday cooking it is close enough. For baking, borrow or buy a scale — it is the single cheapest upgrade to a home baker's accuracy.

Buying it by the kilogram

Shops sell water by weight, and the kilogram is the standard pack size in most countries outside the United States. Knowing that the pack holds about 4.22 cups lets you compare it honestly against smaller packs: a 500 g pack is 2.11 cups, so if the kilogram costs less than twice the 500 g price, it is the better buy — provided you will use it before it goes stale. For water, every kind of cooking, baking and drinks. Work out how many cups your household actually uses in a month before choosing the big pack; a bargain that ends up thrown away is not a bargain. And remember the figure is approximate: if the recipe on the packet is written in grams, follow the grams. Cups are a translation, not the original.

Frequently asked questions

How many cups are in 1 kg of water?

About 4.22 cups. One cup of water weighs 237 g poured (USDA), and 1,000 g ÷ 237 g = 4.22 cups. The figure is approximate, because how firmly the cup is filled changes the weight slightly.

How many cups are in 500 g of water?

About 2.11 cups — half the kilogram figure. The same division applies: 500 g ÷ 237 g per cup = 2.11 cups. The conversion table near the top of the page lists 100 g, 250 g, 750 g, 1.5 kg, and 2 kg as well.

How many tablespoons are in 1 kg of water?

About 68 level tablespoons. One tablespoon of water weighs 14.8 g, so 1,000 g divided by that is 68 spoonfuls. Tablespoons are a workable fallback when there is no scale, but each spoonful adds a little error, so weigh when it matters.

Can I use the same cups-per-kilogram figure for other brands of water?

Usually, yes, within a small margin. The cup weight of a standard ingredient is set by its density, which barely changes between brands. What does change it is the form — fine versus coarse, sifted versus settled, softened versus fridge-hard — so if a brand feels noticeably lighter or denser in the hand, weigh a cup of it once and use your own figure.

Why do different sources give different cup weights for water?

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. This page uses the primary published figure and states it plainly, so you can adjust if your recipe book uses a different one.

Related conversions

More conversions for water, and the tools that do this arithmetic for you: