How Many ml in a Cup? 240, 236.6 or 250 — and When It Matters
October 3, 2026
You have a measuring jug marked in millilitres and a recipe that says 1 cup milk. You search for the answer and get three of them: 240 ml, 236.6 ml and 250 ml. They’re all right. They’re just answers to different questions, and only one of those differences can actually change how a recipe turns out.
The short answer
- US recipes: 1 cup = 240 ml. This is the cup the FDA uses on every US nutrition label, and the one most recipe developers measure with.
- Exact US customary: 1 cup = 236.6 ml. This is the cup as legally defined. It’s about 1.4% smaller, which never matters at the stove.
- Australia, New Zealand and Canada: 1 cup = 250 ml (the metric cup).
- Japan: 1 cup = 200 ml. A Japanese rice-cooker cup is 180 ml, which is smaller again.
If the recipe is American, measure 240 ml. Our cooking measurement converter uses that same 240 ml cup by default and can switch to the other two in one tap.
Cups to ml chart
The same numbers our converter uses. The US kitchen column is the one to use for American recipes:
| Cups | US kitchen (FDA) | Exact US customary | Metric cup |
|---|---|---|---|
| ¼ cup | 60 ml | 59.1 ml | 62.5 ml |
| ⅓ cup | 80 ml | 78.9 ml | 83 ml |
| ½ cup | 120 ml | 118.3 ml | 125 ml |
| ⅔ cup | 160 ml | 157.7 ml | 167 ml |
| ¾ cup | 180 ml | 177.4 ml | 187.5 ml |
| 1 cup | 240 ml | 236.6 ml | 250 ml |
And the other US kitchen measures, on the same two US standards:
| Unit | US kitchen | Exact US customary | In other units |
|---|---|---|---|
| 1 teaspoon | 5 ml | 4.93 ml | ⅓ tbsp |
| 1 tablespoon | 15 ml | 14.79 ml | 3 tsp |
| 1 fluid ounce | 30 ml | 29.57 ml | 2 tbsp |
| 1 cup | 240 ml | 236.59 ml | 16 tbsp = 8 fl oz |
| 1 US pint | 480 ml | 473.18 ml | 2 cups |
| 1 US quart | 960 ml | 946.35 ml | 4 cups |
| 1 US gallon | 3.84 L | 3.785 L | 16 cups |
Going the other way, 250 ml is just over a US cup (1.04 cups) and 500 ml is about 2⅛ cups. The converter shows any amount in every unit at once, so you don’t have to chain conversions.
Why the US has two cups
The exact cup comes from the gallon. A US liquid gallon is legally 231 cubic inches, which works out to exactly 3.785411784 litres. A cup is one-sixteenth of that: 236.5882365 ml, according to Wikipedia’s cup article. Every other US measure divides down from the same gallon, which is why the tablespoon comes out at an awkward 14.79 ml.
Nobody wants to print 236.5882365 on a cereal box. So for nutrition labelling the FDA rounded the whole set. Its guidance on metric equivalents reads: “1 cup means 240 mL, 1 tablespoon means 15 mL, 1 teaspoon means 5 mL, 1 fluid ounce means 30 mL.” That set is the one that ends up in kitchens. It lines up with the 15 ml metric tablespoon and 5 ml teaspoon, and it stays tidy, because 16 tablespoons of 15 ml make exactly 240 ml.
The rounding isn’t quite consistent, though. NIST’s kitchen measurement table agrees on the 240 ml cup, the 480 ml pint and the 3.84 L gallon, but lists the quart as 950 ml. That’s the exact 946 ml rounded, not four 240 ml cups. Our converter keeps the quart at 960 ml so that “1 quart = 4 cups” stays true. If a quart carton says 946 ml, it’s using the exact standard.
Does 240 vs 236.6 actually matter?
No. It’s a 1.4% gap: 3.4 ml, under a teaspoon per cup. Two cooks levelling flour in the same kitchen differ by more than that. Pick either one and use it consistently.
The 250 ml metric cup is 4% bigger than the US cup. That’s still small for a cup of stock, but it starts to show in baking with several cups of flour. If an Australian recipe calls for 3 cups of flour and you measure with US cups, you’re about 30 ml short. Switch our converter to Metric and the cup row becomes the 250 ml cup.
The spoon that does matter
The cup gets the attention, but the tablespoon causes the real damage. Almost everywhere, a tablespoon is 15 ml. In Australia it is 20 ml. Both Wikipedia’s tablespoon article and Australia’s National Measurement Institute say so. That’s a third more per spoon.
A third more vanilla doesn’t matter much. A third more baking soda, salt or gelatin does: the cake tastes soapy, the dough is too salty, the jelly sets rubbery. If a recipe is Australian, measure 4 teaspoons wherever it says 1 tablespoon (4 × 5 ml = 20 ml).
Two more traps: rice cups and pints
Rice cookers. The plastic cup that comes with a Japanese rice cooker is 180 ml, not 200 ml or 240 ml. It’s a traditional unit called the gō, which used to be one serving of rice. The water lines inside the cooker are marked for that cup, so measure rice with it and ignore your other cups.
Pints. A US pint is 473 ml (480 ml on the kitchen standard). A UK pint is 568 ml, about 20% more. The UK pint holds 20 UK fluid ounces, which are slightly smaller than US ones, where the US pint holds 16. A British recipe asking for a pint of milk means the bigger one.
A fluid ounce is not an ounce
A fluid ounce is a volume, about 30 ml. An ounce is a weight, 28.35 g. The two only line up for water and liquids of similar density. Honey is the classic example. King Arthur Baking’s ingredient weight chart puts a cup of honey at 340 g, so one fluid ounce of honey weighs about 1.5 oz. A recipe that says “8 oz honey” and one that says “1 cup honey” are asking for different amounts.
That’s why the cooking measurement converter keeps volume and weight separate. Turning cups into grams depends on what’s in the cup. For that, use the cups to grams converter, which knows the density of 100+ ingredients. If you’re converting butter, the butter converter works in sticks. If you’re doubling or halving the recipe as well, the recipe scaler does both steps at once.
The takeaway
For American recipes, a cup is 240 ml and a tablespoon is 15 ml. Don’t let the 236.6 ml cup worry you. What deserves attention is where the recipe comes from: a 250 ml cup in Australia, New Zealand or Canada, a 20 ml tablespoon in Australia, a 568 ml pint in Britain, and a 180 ml cup in your rice cooker.