How many cups is 100 g of water?

100 g of water is about 0.42 cups.

Why isn't 100 g exactly 1 cup?

Because water isn't the same density as water. A cup holds a fixed volume, and water weighs more or less than water for that volume.

Grams of water to cups

Answer

100 g of water = 0.42 cups

Convert any amount

Amount gram = – cup

Conversion table

Grams	Cups
10 g	0.04 cup
25 g	0.1 cup
50 g	0.21 cup
100 g	0.42 cup
150 g	0.62 cup
200 g	0.83 cup
250 g	1.04 cup
300 g	1.25 cup
500 g	2.08 cup

Based on the US customary cup of 240 ml. A metric cup (250 ml) is about 4% larger.

Handy tools for this

Digital kitchen scale The most accurate way to bake — skip the cup guesswork and weigh straight into the bowl to the nearest gram. Check price → Measuring cups set A sturdy nested set of US cups for recipes written in cups. Cheap, dishwasher-safe and built to last. Check price → Measuring spoons Tablespoon and teaspoon set for small, precise amounts of baking powder, salt and spices. Check price →

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How to measure

Water is the reference point: 1 millilitre weighs exactly 1 gram, so 1 dl = 100 g and 1 litre = 1 kg.

Frequently asked questions

How many cups is 100 g of water?: 100 g of water is about 0.42 cups.
Why isn't 100 g exactly 1 cup?: Because water isn't the same density as water. A cup holds a fixed volume, and water weighs more or less than water for that volume.

Related conversions

Values are approximate — ingredient density varies with brand, humidity and how you measure. For baking, weighing on a scale is always the most reliable method.