Cups to Milliliters conversion

How big is a cup?

The cup is the workhorse of American recipes, but it is not a single well-defined unit. The US customary cup used in most cookbooks is 236.588 ml (half a US pint). The "legal" cup printed on US nutrition labels is a rounded 240 ml. The metric cup used in Australia, New Zealand and many modern recipes is 250 ml, and the old imperial cup was about 284 ml. This converter uses the US customary cup of 236.588 ml, the value behind nearly every recipe written in cups.

Cups to milliliters

Multiply the number of cups by 236.588. For everyday cooking, rounding to 240 ml per cup (or even 250 ml) rarely changes the outcome; for baking, where ratios matter, stay closer to the exact figure.

• 1/4 cup = 59 ml
• 1/3 cup = 79 ml
• 1/2 cup = 118 ml
• 2/3 cup = 158 ml
• 3/4 cup = 177 ml
• 1 cup = 237 ml
• 2 cups = 473 ml (one US pint)
• 4 cups = 946 ml (one US quart)

Cups are volume, not weight

A cup of water weighs 237 g, but a cup of flour weighs around 120–130 g and a cup of sugar about 200 g. Converting cups to milliliters is exact; converting cups to grams depends entirely on the ingredient. If you own a kitchen scale, look for recipes that give grams — they are more repeatable.

Measuring liquids correctly

Use a transparent measuring jug on a flat surface and read the level at eye height. Measuring cups meant for dry ingredients are designed to be levelled off with a knife and will under-measure liquids if you try to fill them to the brim without spilling.

Coffee cups and tea cups

A coffee "cup" on a drip machine is often only 150 ml, and a tea cup can be anything. When a recipe says "cup", it means the measuring cup, never the mug on your desk.

Worked examples

2¼ cups of flour. 2.25 × 236.588 = 532 ml by volume — but flour is better weighed: 2¼ cups is about 280 g.

⅓ cup of oil. 0.333 × 236.588 = 79 ml. A metric measuring jug marked in 25 ml steps reads this as "a bit over 75".

6 cups of stock. 6 × 236.588 = 1 420 ml — one and a half 1-litre cartons.

Frequently asked questions

How many ml are in a cup? 236.6 ml for the US customary cup; 240 ml on US nutrition labels; 250 ml for the metric cup used in Australia and many modern recipes.

Is a coffee mug a cup? No. Mugs hold 300–400 ml. When a recipe says "cup", use a measuring cup.

How many cups are in a liter? 4.23 US cups, or exactly 4 metric cups.

Related conversions

Smaller amounts are easier in tablespoons (16 per cup, 14.8 ml each) — see tablespoons to milliliters. Fluid ounces to milliliters covers the 8 fl oz that make a cup.

Good to know

The cup measure only makes sense for scaling: doubling or halving a recipe in cups is trivial, and that is why American recipe writers kept it. When you convert to millilitres, keep that convenience by rounding to numbers your jug can show — 237 ml becomes 240 or 250 ml, 118 ml becomes 120 ml. The only place the 5 % difference between a US cup and a 250 ml metric cup shows up is in baking that depends on ratios, such as bread, choux pastry and custards; there, either measure everything in the same cup or switch to grams and forget cups entirely.