Cups to ML Converter (US, Metric & UK Cups)
One US cup is 236.6 ml, one metric cup is 250 ml and one old UK cup is 284.1 ml. This page converts all three.
Which cup does your recipe use?
A cup is not one fixed size. The US customary cup is 236.6 ml. The metric cup used in Australia, New Zealand, South Africa and in current Canadian recipes is 250 ml, which is 5.7% bigger. The old British cup, from the era of imperial measures, is 10 imperial fluid ounces or 284.1 ml (20% bigger than the US cup), and you will only meet it in vintage cookbooks.
Two near neighbors cause confusion. US nutrition labels define a cup as 240 ml for serving sizes, which is a labeling convention and not the measuring cup in your drawer. Japanese recipes use a 200 ml cup. If a recipe does not say where it is from, look at the other units: a recipe that also lists grams, “caster sugar” or “plain flour” is probably using a metric cup.
Cups to ml table
Read across to compare the three cups. The ml columns are the same for every ingredient, since this is a pure volume conversion.
| Cups | US cup (ml) | Metric cup (ml) | UK cup (ml) |
|---|---|---|---|
| 1/8 cup | 29.57 | 31.25 | 35.52 |
| 1/4 cup | 59.15 | 62.5 | 71.03 |
| 1/3 cup | 78.86 | 83.33 | 94.71 |
| 1/2 cup | 118.3 | 125 | 142.1 |
| 2/3 cup | 157.7 | 166.7 | 189.4 |
| 3/4 cup | 177.4 | 187.5 | 213.1 |
| 1 cup | 236.6 | 250 | 284.1 |
| 1 1/2 cups | 354.9 | 375 | 426.2 |
| 2 cups | 473.2 | 500 | 568.3 |
| 3 cups | 709.8 | 750 | 852.4 |
| 4 cups | 946.4 | 1,000 | 1,136.5 |
Why the cup size changes the result
Swapping a 250 ml cup for a 236.6 ml one changes the volume by 5.7%, and a cake is sensitive to that. One cup of all-purpose flour is 120 g with a US cup and 127 g with a metric cup, a gap of 6.8 g per cup. Over the three cups in a loaf recipe that is 20.41 g of extra flour. Use the ingredient converter and pick the cup that matches the recipe to get grams for each.
Worked example: 2¼ cups of milk in ml and grams
- US cups to ml: 2.25 × 236.6 ml = 532.3 ml.
- If it is a metric-cup recipe: 2.25 × 250 ml = 562.5 ml.
- To weigh the US amount, milk is 244 g per US cup (Milk, whole, 3.25% (fdcId 171265): 1 cup = 244 g; 1 tbsp = 15 g): 2.25 × 244 g = 549 g.
Quick rules of thumb
- 1 US cup is a little under ¼ liter. A liter is 4.23 US cups or exactly 4 metric cups.
- For rough work, 1 US cup ≈ 240 ml is fine for soups and stocks. Do not round for baking.
- Liquid measuring cups are read at eye level on a flat surface. Dry measuring cups are filled and levelled.
Related tools
Frequently asked questions
How many ml are in a cup?
A US cup is 236.6 ml, a metric cup is 250 ml and a UK (imperial) cup is 284.1 ml.
Is 1 cup 240 ml or 250 ml?
It depends on the recipe. US measuring cups hold 236.6 ml (often rounded to 240 ml), and the metric cup holds exactly 250 ml. Use 250 ml for Australian, New Zealand and South African recipes.
How many cups is 500 ml?
500 ml is 2.11 US cups (about 2 cups + 1 tbsp + 2 tsp) or exactly 2 metric cups.
How many cups are in a liter?
A liter is 4.23 US cups, 4 metric cups, or 3.52 UK cups.
Does a cup of flour weigh the same in every country?
No, because the cups differ. A US cup of all-purpose flour is 120 g and a metric cup is 127 g. Check the cup size first.
Why is my US measuring cup marked 237 ml?
The exact US cup is 236.6 ml. Many cups round this to 237 ml, and some nutrition-label cups to 240 ml. The difference is small enough to ignore except in precise baking.