The Right Size: How Many Ounces In A Coffee Cup?

How many ounces in a coffee cup? How can you get your morning cup of coffee exactly right? Take a look at how you can get the correct coffee to water ratio! 

how many ounces in a coffee cup - measuring glass in liter and ounce filled with espresso
The metric system declares a single “cup” to be 250 mL which is approximately 8.5 fluid ounces

If you are like me, the first thing you do when you get up in the morning is to go to your coffee maker. There is no way your day is going to be successful unless you get your morning cup of coffee! When you open the cabinet, you probably realize that you have numerous coffee mug sizes. 

How many fluid ounces equals 1 cup of coffee? If you go to a coffee shop such as Starbucks, the barista probably has multiple sizes available such as tall, grande, and venti. Then, an espresso cup, a cappuccino, and a latte might have different sizes as well.

Whether you are looking to make specialty coffee, traditional coffee, or a different drink entirely, it’s important to understand how many fluid ounces equals one cup of coffee!

One Cup Equals Eight Fluid Ounces, Right?

If you grew up in the United States, you probably learned that a single cup is 8 fluid ounces whether you are making a cup of coffee, a teacup, or using a measuring cup to bake something. You might be surprised to hear that a “cup” means different things in different places. 

For example, most places in the world use the metric system. The metric system declares a single “cup” to be 250 mL. This equals close to 8.5 fluid ounces.

On the other hand, Japan declares one cup to be 200ml. This is just under seven fluid ounces. If you were to take a look at the Chemex brewer, you would see that a single cup is actually five fluid ounces. 

So, who is correct? If you don’t know exactly how many fluid ounces you are supposed to make, you’ll have a hard time getting your cup of coffee to taste right!

Get the Ratio of Water to Coffee Correctly

weighing whole beans of coffee
Aim for 1.5 to 2 grams of whole-bean coffee per 28 grams of water

Some people might be wondering why the size of a coffee cup even matters. It matters because you need to get the ratio right. If you are trying to make a cup of coffee, you need to know what is meant by a “cup.”

Otherwise, you might add too much water, too few coffee grounds, and mess up your ratio. It is not the amount of water or the number of coffee beans you use in your coffee machine. It is the ratio of the two that makes your coffee taste delicious. 

Fortunately, there are other ways you can measure your coffee. Instead of using a measuring cup, use a scale. Depending on how strong you want your coffee, you need to aim for a coffee to water ratio that equals 1.5 to 2 grams of whole-bean coffee per 28 grams of water.

Therefore, if you are trying to make 16 fluid ounces of coffee (which would be two “typical” cups), you need between 26 and 32 grams of coffee. When it comes to a coffee mug in the United States, 16 fluid ounces is a standard! Or, you can share with someone else and make two 8-ounce cups. 

If you want to get your coffee right, you should use a scale. Particularly if you are using coffee beans, you will have a hard time measuring 1 “cup” of coffee beans. Because coffee beans do not sit evenly, there are going to be open spaces in your measuring cup.

You will have a hard time getting the right measurement with a typical cup. Therefore, invest in a kitchen scale instead. You will have an easier time getting your measurements correct.

Make sure you zero the kitchen scale before you use it to ensure your measurements are accurate!

The Final Word on How Many Ounces in a Coffee Cup

In the end, there isn’t really a standard coffee cup size. The standard cup size varies from place to place. If you are making coffee in the morning, you simply need to make enough to meet your needs.

Even though 8 fl oz of water does equal 1 measuring cup, most of the world uses the metric system. This can make it hard to get your measurements correct. Therefore, use a kitchen scale instead. 

Coffee lovers may find a kitchen scale useful for other hot beverages as well. When you do the kitchen scale, make sure you use grams. That way, you know exactly how much coffee and water you are adding.

Remember that it is the ratio of coffee grounds to water that makes for a delicious cup of coffee. 

FAQs About How Many Ounces in a Coffee Cup

What is the best ratio of coffee to water? 

The ideal ratio of coffee to water is 1.5 to 2 grams of whole-bean coffee for 26 grams of water. If you like your coffee to be a bit stronger, you may want to use closer to 2 grams of coffee. If you like your coffee to be a bit weaker, you may want to use closer to 1.5 grams of coffee. You can adjust the ratio to make the taste match your preferences.

How many ounces are in a cup?

If you are using the standard system, 8 fluid ounces equals one cup. You may find that it is easier to use the metric system. If you are converting ounces to milliliters, one fluid ounce is 28.41 mL.

Why is it difficult to measure coffee beans using a cup?

If you are using a measuring cup to measure coffee beans, there are going to be open spaces in your measuring cup. Coffee beans are of different shapes and sizes. They do not layer evenly. Therefore, if you pour coffee beans into a measuring cup, you are actually going to have slightly less than one cup of coffee beans. There are open gaps in the cup, reducing the amount of coffee you are using.


  • David R

    Job experience includes extensive work as a teaching assistant, tutor, and guest lecturer and extensive employment in the healthcare field. Have published multiple research papers and numerous poster presentations on various healthcare research topics. Find David on WriterAccess.