Popcorn Yield Calculator

One cup of unpopped popcorn kernels typically yields 35 to 50 cups of popped popcorn, depending on the kernel variety and popping method. Butterfly popcorn averages around 40-45 cups per cup of kernels, while mushroom popcorn yields about 35-40 cups. Our calculator uses a default expansion ratio of 40:1 with 98% popping efficiency.

Butterfly popcorn has an irregular, wing-like shape with many protruding "wings." It's lighter, fluffier, and has a higher expansion ratio (40-50×). It's the most common type for home popping and movie theaters.

Mushroom popcorn pops into a round, compact ball shape. It has a lower expansion ratio (35-40×) but is sturdier, making it ideal for caramel corn, kettle corn, and coated popcorn since it doesn't break as easily.

Unpopped kernels, often called "old maids," usually fail to pop because they lack sufficient moisture inside the hull. Popcorn kernels need about 13-14% internal moisture to create the steam pressure that causes them to explode. Kernels that are too dry, have cracked hulls, or are old may not pop. Typical popping efficiency is 90-98%. Storing kernels in an airtight container helps preserve moisture.

There are 16 tablespoons in 1 US cup. So if a recipe calls for 3 tablespoons of kernels (common for a microwave bag), that's approximately 0.19 cups, which yields about 7-9 cups of popped popcorn. A standard microwave popcorn bag typically contains 2.5-3.5 tablespoons of kernels.

For a party of 10, plan on about 3-4 cups of popped popcorn per person if it's a snack alongside other foods, or 6-8 cups per person if popcorn is the main treat. That means you'll need roughly ¾ to 1½ cups of unpopped kernels total (about 30-60 cups popped). Use the reverse mode in our calculator to find the exact amount!

Air-popped popcorn has about 30-31 calories per cup. One cup of unpopped kernels (~160-180g) yields about 40 cups popped, totaling roughly 1,200 calories for the entire batch (without toppings). Oil-popped popcorn adds about 40-55 calories per cup depending on the oil used. Butter and other toppings add extra calories.

Store kernels in an airtight container in a cool, dry place (like a pantry). Avoid the refrigerator, as it can dry out kernels. Properly stored, popcorn kernels can last 2+ years while maintaining good popping efficiency. If your popping rate drops below 85%, the kernels may have lost too much moisture.

Approximately: 1 cup of unpopped kernels ≈ 160-180 grams ≈ 5.6-6.3 ounces. This can vary slightly by variety and moisture content. Our calculator uses 170g per cup as the standard conversion for weight-based inputs. For popped popcorn, 1 cup weighs only about 8-10 grams due to the increased volume.