How Many ML in a Cup? US, UK and Metric Cups Explained
If you’ve ever followed a recipe from a different country, you’ve probably wondered how many ml is in a cup. The answer isn’t as simple as you’d think — because a cup in the US is a different size to a cup in the UK, Australia and the rest of the metric world.
This guide explains everything you need to know about cup measurements and how to convert them to millilitres accurately.
How Many ML in a Cup?
The most common cup measurement is the US cup, which equals 236.588 ml — usually rounded to 237ml for everyday use.
But there are actually three different cup sizes used around the world:
- US cup — 236.588 ml (most common in recipes)
- UK/Imperial cup — 284.131 ml (older British recipes)
- Metric cup — 250 ml (Australia, Canada, New Zealand)
This difference matters more than you’d think. If a US recipe calls for 2 cups of flour and you measure using a metric cup, you’d be adding an extra 27ml per cup — over a full recipe that adds up.
US Cup vs Metric Cup — What’s the Difference?
The US cup originated from the old US customary system and was standardised at 8 US fluid ounces, which works out to 236.588ml.
The metric cup used in Australia, Canada and New Zealand is a rounder 250ml — exactly a quarter of a litre. It’s simpler and more consistent with the metric system.
The difference between a US cup and a metric cup is 13.4ml — small for a single cup but significant when a recipe uses 4 or 5 cups.
Which cup does your recipe use?
- American recipes — use US cup (237ml)
- Australian, Canadian or NZ recipes — use metric cup (250ml)
- Older British recipes — use imperial cup (284ml)
- Modern British recipes — usually use metric measurements in grams and ml rather than cups
Common Cup to ML Conversions
Here are the most searched cup to ml conversions:
| Cups | US (ml) | Metric (ml) |
|---|---|---|
| ¼ cup | 59 ml | 63 ml |
| ⅓ cup | 79 ml | 83 ml |
| ½ cup | 118 ml | 125 ml |
| ¾ cup | 177 ml | 188 ml |
| 1 cup | 237 ml | 250 ml |
| 2 cups | 473 ml | 500 ml |
| 4 cups | 946 ml | 1,000 ml |
How Many ML is 1/3 Cup?
One third of a US cup is approximately 79ml. One third of a metric cup is approximately 83ml. This is one of the most commonly searched conversions — particularly for baking recipes that use ⅓ cup measurements for ingredients like oil, yoghurt or syrup.
How Many ML is Half a Cup?
Half a US cup is 118ml. Half a metric cup is 125ml. Half a cup is one of the most frequently used measurements in baking — for liquids like milk, water and oil as well as dry ingredients like sugar and flour.
How Many ML is 2 Cups?
Two US cups equals 473ml — just under half a litre. Two metric cups equals exactly 500ml — half a litre. If you’re making a recipe that requires 2 cups of liquid, 500ml is a convenient approximation that works for most purposes.
Why Do Recipes Use Cups Instead of ML?
Cup measurements were standardised in American cooking in the late 1800s and became deeply embedded in US recipe culture. The advantage of cups is speed — you can scoop and level dry ingredients quickly without a scale. The disadvantage is inconsistency — a loosely packed cup of flour weighs significantly less than a tightly packed one.
Most professional bakers and international recipes use weight measurements in grams for precision. If accuracy matters — especially for baking — weighing ingredients on a kitchen scale is more reliable than cup measurements regardless of which cup size you use.
Convert Cups to ML Instantly
Rather than calculating by hand, use our free Cups to ML Calculator to convert any cup measurement to millilitres instantly — with support for US cups, metric cups and UK imperial cups.
FAQs
How many ml is a cup of water?
A cup of water is 237ml using a US cup or 250ml using a metric cup.
How many ml is a cup of milk?
A cup of milk is 237ml using a US cup or 250ml using a metric cup. Milk and water have virtually the same volume measurement.
Is 250ml the same as 1 cup?
250ml equals exactly 1 metric cup, used in Australia, Canada and New Zealand. It’s slightly more than 1 US cup which is 237ml.
How many cups is 500ml?
500ml is approximately 2.11 US cups or exactly 2 metric cups.
How many cups is 1 litre?
1 litre is approximately 4.23 US cups or exactly 4 metric cups.