The world is accustomed to different measurement units like grams, tablespoon, ounces, litres and more. Measurement units are used for many things but most importantly when cooking. Recipes require cooks to measure out the ingredients to cook a particular dish. Inability to follow the recommended measurements may lead to a bad food experience.

But what if the measurements aren’t clear? You may be wondering, how can that be possible? Measurements are a simple standard across the world, so how can it not be clear unless you can’t read the recipe properly?

Well, that’s not the case. Sometimes recipes might state using one or two onions while other times it may just say a cup of onions. You may be asking yourself “Well, how many onions in a cup?” but it’s not that simple because onions come in different sizes. Such recipes can create challenges because unclear instructions often lead to wastage of time and distasteful food.

How many onions in a cup?

So you’ve finally come across a recipe that requires a cup or two of onions and now you’re wondering how many onions is a cup of onion. It’s fairly simple to remember so let us guide you. Typically, onions come in three sizes; small, medium and large. Now let’s see how many different sized onions equals a cup.

A small onion is equal to a third of a cup meaning three small onions diced is a single cup of onion.

A medium onion is equal to a single cup of onion (The answer you’ve all been looking for!).

A large onion is equal to a cup and a half of onions meaning two large onions diced is equivalent to three cups of onions.

Four medium sized onions is equal to a pound of onion which is almost 4 cups of diced onions.

We understand that size can be perceived differently by everyone. A small onion can seem like a medium onion to some people and vice versa. There are cases where some might peel off or cut off more than others while cleaning an onion. This can create a lot of uncertainties and therefore there is no particular answer to the question “how many onions in a cup?”.

Our ultimate onion guide aims to provide reasonable estimates so that you don’t waste your time pondering on the onion in a cup question.

Now that we’ve got this figured out, what if the recipe requires red onions and you have yellow? Can you substitute a red onion with a yellow one in your dishes?

Worry not as we have compiled this guide to ensure that you understand measurements as well as the different types of onions. This will help you in understanding how an onion substitution might affect your dish.

The ultimate onion guide

We’ve already discussed how many onions in a cup, now let’s look at some of the most common types of onions.

White Onions

These are your regular standard onions that have a kick to it meaning they are more stronger in flavor and tend to lean on the spicier side. White onions have a much thinner skin than the other types of onions. Recipes like tacos, salsa and other spicy cuisines usually require the use of white onions.

Yellow Onions

These can be found in most kitchens because they are very versatile. These kinds of onions are the basic for any recipe that requires “an onion”. Yellow onions are great for caramelization as they release their natural sweetness when in contact with heat. Yellow onions have a much larger storage life than the other types of onions however it is not recommended to consume them raw as they are high in sulfur. This can lead to one having a seriously bad onion breath.

Red Onions

These are just like yellow onions when it comes to versatility as it can be substituted in a dish if you don’t have yellow onions available. However, red onions are much sweeter than yellow onions and can be consumed raw. This is why most salads will have red onions in them instead of yellow. Red onions can also be found in pizza, sandwiches and more. Believe it or not, red onions are used to make onion jam.

There are other types of onions as well like leeks, shallots, green onions and more. However, most of the onions besides white, yellow and red are not that commonly used in dishes but rather used as garnishes.

We hope that our ultimate onion guide was able to answer your question of how many onions in a cup and also help you differentiate among the three most common types of onions. Stick around to keep yourself updated on cool recipes, kitchen troubleshoots and more.