Experienced cooks can measure the amount of food or liquid simply by eyeballing and they can do in milliliters, grams, ounces or cups. But for an ordinary housewife it is not a simple task, and converting units is even more difficult.
Ounces and Cups
Ounces and cups are units of volume which are often used in many British, American and Canadian cooking books, especially old ones. Though almost everybody knows how much an ounce1 is, sometimes it is not easy to understand how many ounces there are in one cup.
The problem is that not all known cups are equal in volume, because the definitions of the cup are different in various systems.
What is more, US customary ounces and imperial ounces are also different in sizes, and the US variant is approximately 4% larger than the UK one. Cup is a volume unit used in recipes for measuring liquids and some foods. There are several cup sizes (US, imperial, Japanese, and metric). And all of them are substantially different in sizes.
If you don’t use ounces and cups from different systems, you can remember this:
1 US customary cup is equivalent to 8 US fluid ounces
1 imperial cup is equivalent to 10 imperial fluid ounces
1 imperial cup equals to 1.2 US cups
As you see, Americans and British can give different answers to the question, “How many ounces are there in a cup?”
Converting measurement units from various systems can be a serious problem which is solved easily with the help of this conversion chart. You will hardly find imperial cups nowadays, but we have added them to the table for any emergency. You should also understand the difference between US customary and US legal cups, which is seen from the table.
Imperial Fluid Ounces
US Customary Fluid Ounces
Imperial cup (used in British Commonwealth of Nations)
Metric cup (used in Canada, Australia, and New Zealand)
US customary cup
US legal cup
Go (traditional Japanese cup)
Some recipes can confuse you because foods are measured in liquid units in them (for example, 2 cups of diced celery). If you want to know how much it is in ounces but you don’t have scales in the kitchen, you can get some answers from the chart below.
Ounce (abbr. oz) is a widely-spread unit of mass or volume (fluid ounce), which is used in various systems and has several definitions. The most common definition is equivalent to approximately 28 grams.