It’s a common food cost question when figuring out how much product to order and what your yield will be.
TLDR:
- A small onion could produce about 1 cup of diced onion.
- A medium onion might yield around 1 1/2 cups of diced onion.
- A large onion could result in 2 cups of diced onion.
Onions are a staple ingredient in professional kitchens around the world, valued for their ability to add depth, flavor, and aroma to a myriad of dishes. When I was in Chef’s school in Sault Ste. Marie, Ontario way back in the 1980’s I remember our Head Instructor Chef Heilimo instructor saying (with a heavy Finnish accent), “There’s not much you can do in a kitchen without onions.” He was right!
For professional chefs, particularly those keen on optimizing food costs and minimizing waste, understanding the yield of usable onion from a whole, unpeeled onion is a basic food cost calculation that comes up frequently.
The yield of usable onion from a whole, unpeeled onion varies significantly based on size and the method of preparation. Generally, the process of peeling and trimming the ends results in a loss of about 15-20% of the onion’s initial weight. This percentage can increase if the outer layers are particularly dirty, spoiled or damaged and require removal.
Onion Sizes and Usable Yields
- Small Onions: Yield approximately 50-60 grams of usable onion.
- Medium Onions: Yield around 80-95 grams of usable onion.
- Large Onions: Yield approximately 120-130 grams of usable onion.
These yields can vary based on the specific type of onion and its condition before peeling. For precise recipes and food costing calculations, it’s useful to note that a cup of diced onion typically weighs approximately 160 grams.
While onion rings are a popular side dish, they result in a higher waste percentage. This is because only the larger, more aesthetically pleasing rings are used. Depending on the onion size and the desired ring thickness, you might find that up to 30-40% of the onion is wasted when discarding the smaller inner rings and outer layers that are not suitable for your dish. So this is also a calculation that seriously erodes the actual yield of the raw product.
However, a good chef knows the axiom: waste not, want not. The trimmings from onions, including the root ends, outer layers, and smaller rings, can be repurposed effectively in the kitchen. These bits are excellent for adding flavor to stocks, broths, and soups. Simply wash the trimmings well to remove any dirt and store them in a freezer-safe bag or container until you have enough to make a batch of stock. Not only does this approach reduce waste, but it also contributes to a more sustainable and thoughtful kitchen practice.
We normally only buy 50Lb bag of onions – usually the large size. So understanding the quantity you’re getting is essential for effective kitchen planning and budgeting. Considering that a large onion typically weighs about 250 grams (approximately 0.55 pounds), you can expect to find around 90 to 100 large onions in a 50 lb bag. This is a good guideline for chefs in menu planning, inventory control, and ensuring the optimal use of every onion purchased. It’s worth noting that the actual count may vary slightly depending on the specific weight of the onions in your bag, so weighing a sample from your batch can provide a more exact figure.
I always tend to underestimate my yield so I would normally have an 80% yield in my food cost program for any type round onions I buy. Hopefully I get better than that, but this helps buffer my food cost estimates so as to help my budget come in under my target food cost.
Here is a screenshot of my food cost spreadsheet for whole onions showing the cost per gram after the yield factor was taken into account. So for any recipe that called for onions I use the cost AFTER yield has been applied.
For non-pro cooks reading this, I am including a Gordon Ramsay video that shows how to dice an onion.
