Bridging the gap between grocery shopping and kitchen prep too often requires excessive guesswork. How many mush­rooms do you need for the 1 cup sliced your recipe calls for? How many cloves are in a table­spoon of minced garlic? Many recipes leave it up to the reader to decode these mysteries, leading to befuddlement at the supermarket and frustration at home.

To clear things up, we tested a variety of common items to determine their yield after being chopped, pureed or otherwise prepared to be used in a recipe.

Our testing revealed many useful rules of thumb. A single medium onion produces 1 cup of chopped onion. To make 1 cup of whipped cream, you’ll need to start with ½ cup of heavy cream. And for every cup of pureed pumpkin, you will need roughly a pound of raw squash.

Of course, some foods are easier to measure at the store than others. It’s simple to know how much you are buying with packaged foods, such as heavy cream and cheeses. But the variability of produce can make this more challenging. To help, we’ve offered weights and visual cues where appropriate and suggest that when in doubt, use the scale.

Kitchen Counts
Raw to Prepped Conversions
Apple1 med. apple (6 oz.)1 c. ½-inch cubes or 1¼ c. ¼-inch slices
Butternut Squash/Pumpkin/Sweet Potato1½-2 lbs. cleaned2 c. cooked puree
Cremini Mushrooms6 med mushrooms (2¾ oz.)1 c. sliced
Flat-Leaf Parsley4-oz. bunch1½ c. leaves or ⅔ c. chopped
Fresh Ginger3-in. piece (3 oz.)2 tbsp. finely grated
Garlic8 med. cloves (1 oz.)2 tbsp. minced
Heavy Cream1 c. (8 oz.)2 c. whipped
Jalapeño1 med jalapeño (1 oz.) seeded3 tbsp finely chopped
Onion1 med. onion (8 oz.)1 c. chopped or 2 c. sliced
Popcorn¼c. kernels10 c. popped
Potatoes2-2½ lbs.4 c. mashed
Rustic Country Bread1-lb loaf12 c. (1-inch cubes)
Scallions4-oz. bunch½ c. thinly sliced whites + 1⅓ c. thinly sliced greens
Semifirm Cheese (e.g., Cheddar or Gruyère)3 oz.1 c. shredded (large holes of box grater)
Spinach10 oz.2 c. cooked and drained