How many cups does a microwave bag of popcorn make?

Microwave popcorn bags typically contain between 2 to 3 tablespoons of unpopped popcorn kernels. This translates to around 3-4 cups of popped popcorn per bag, though the exact amount can vary between brands and popcorn bag sizes.

Factors That Affect Popcorn Yield

There are several factors that affect the final popped popcorn yield from a microwave popcorn bag:

Amount of Unpopped Kernels

More unpopped kernels in the bag = more popped corn. Standard microwave popcorn bags contain about 2-3 tablespoons of kernels. Jumbo bags may have around 1/4 cup or more.

Popcorn Type

The type of popcorn affects popped volume. Yellow butterfly popcorn tends to be lighter and fluffier when popped compared to white mushroom popcorn. So butterfly popcorn may yield slightly more cups per bag.

Kernel Freshness

Fresher popcorn kernels will generally pop up bigger. Older kernels can dry out over time, resulting in less expansion and shriveled popped corn. So fresher bags may yield more cups.

Moisture Content

The ideal moisture level for popping popcorn is around 13-14%. If kernels are too dry they won’t pop as fully. Wetter kernels can lead to dense popcorn. Kernels dried to the right moisture level maximize pop volume.

Popping Power of Microwave

Higher wattage microwaves generally do a better job of popping all the kernels fully. Lower wattage microwaves may underpop some kernels, reducing final yield.

Cooking Time

Cooking for the recommended time ensures maximum popping. Undercooking can lead to unpopped kernels and less total popcorn. Going over time can burn popcorn.


Higher altitudes cause water to boil at lower temperatures. This can make it harder for popcorn to pop fully at high altitudes. So popped volume may be a bit less.

Standard Microwave Popcorn Bag Sizes

Here are some typical sizes of microwave popcorn bags and how much popcorn they make:

Single Serving Bags

  • 2.5 oz bag – Yields ~2 cups popped popcorn
  • 3.5 oz bag – Yields ~3 cups popped popcorn

Movie Theater Style Bags

  • 5.5 oz bag – Yields ~4 cups popped popcorn
  • 7.5 oz bag – Yields ~5 cups popped popcorn

Jumbo Bags

  • 9.5 oz bag – Yields ~6 cups popped popcorn
  • 10.5 oz bag – Yields ~7 cups popped popcorn

Measuring Popped Popcorn in Cups

When measuring out cups of freshly popped popcorn, it’s best to lightly pack it into the measuring cup without crushing the popcorn. Packing it tightly would compress the popcorn and result in fewer cups. Here are some tips for getting an accurate cup measurement of popcorn:

Use a Dry Measuring Cup

A dry measuring cup specifically made for measuring dry foods like flour, sugar, etc. is best for getting an accurate popcorn quantity. The cups come in nested sets with different cup sizes like 1/4 cup, 1/3 cup, 1/2 cup, etc.

Level Off the Top

Lightly fill the measuring cup with popcorn, then level it off by swiping a knife or other flat utensil across the top to get an accurate cup amount. Don’t pack it down.

Avoid Overfilling

It can be tempting to overfill measuring cups with extra heaped popcorn. But this will throw off the cup count. Stick to level full cups for an accurate popcorn yield.

Count in Full Cups

The final tally is easiest if you measure out in full cup increments vs. partial cups like 1/4 cup, 1/3 cup, etc. Just round any odd leftover amount to the nearest full cup.

Weigh for Extreme Precision

If you want to get super precise, you can weigh the popcorn on a food scale after popping. The general conversion is that 1 cup of popped popcorn weighs about 0.25 ounces. So divide the total weight by 0.25 ounces per cup to get the cup count.

Popcorn Bag Size Calculator

Here is a handy calculator to estimate cups of popped popcorn based on unpopped kernel amount:

Unpopped Kernels Estimated Cups
2 Tbsp ~3 cups
3 Tbsp ~4 cups
1/4 cup ~5 cups
1/3 cup ~6 cups
1/2 cup ~8 cups

Keep in mind these are rough estimates. Actual yield can vary based on the factors discussed earlier. Measuring popped cups directly gives the most accurate result.

Tips for Maximizing Popcorn Volume

Here are some tips to help maximize the popped popcorn yield from your microwave bags:

Buy Freshly Packaged Bags

Check for best by dates on bags and buy freshly produced ones. Old popcorn may have lower moisture content.

Store Properly

Keep unpopped bags sealed at room temperature in a pantry. Refrigerating can dry kernels out.

Let Bag Sit Before Cooking

Let bag sit at room temp 30 minutes before microwaving so moisture evenly distributes.

Use Higher Power Microwave

1100+ watts optimizes popping power. Lower wattage less effective at popping all kernels fully.

Follow Cooking Directions

Closely follow recommended cook times and power levels for that brand popcorn bag.

Listen for Pops Slowing

Stand by microwave and stop cooking when popping starts slowing to 2-3 seconds between pops.

Weigh Bag Before & After

Weigh unpopped bag, then weigh popped bag. Compare weights to see how much water evaporated during popping to optimize technique.

Re-pop Unpopped Kernels

Pick out any un-popped or partially popped kernels and re-pop in microwave in small bowl with a bit of water.

Common Questions

Does a bigger popcorn bag always equal more cups?

Not necessarily. Some jumbo microwave popcorn bags simply contain bigger kernels that may not pop dramatically bigger. Check the unpopped kernel weight rather than bag size for a better indicator of projected popcorn yield.

Why does my popcorn sometimes burn or not pop fully?

Overcooking can scorch popcorn. Undercooking leaves kernels unpopped. Follow instructions closely and stop cooking immediately when popping slows way down. Also listen for the popping rhythm to help identify when it’s done.

How long does popped popcorn last?

Freshly popped popcorn is best eaten immediately. But stored in an airtight container at room temperature, it will retain quality for 2-3 days. Refrigeration can cause moisture loss and make it stale faster.

Can you reheat leftover popcorn?

Yes, popcorn can be reheated but microwaving may cause it to lose crispness. Oven heating on low temp (~250°F) helps retain texture better without drying it out too much.

Why does my homemade stove-popped popcorn pop bigger?

Stovetop popping allows using high heat and oil to maximize popcorn expansion. It also starts with raw kernels freshly added vs. pre-portioned bags. So you can control oil amount, heat level, and kernel ratio to optimize each batch.


Most standard microwave popcorn bags contain 2-3 tablespoons of kernels and pop around 3-4 cups of popcorn. Factors like popcorn type, kernel freshness, and cooking technique affect popped volume. Measuring the finished popcorn in cups gives a more accurate yield than relying on bag size alone. Following proper storage and cooking methods can help maximize the cups you get from each bag.

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