How many grams is a cup of Rice Krispies?

December 27, 2025 •

4 min read

According to Sweet 2 Eat Baking, a comprehensive list of cereal conversions, a standard 1-cup serving of Rice Krispies cereal weighs approximately 27 grams. This is an important detail for anyone looking for precise measurements, especially when baking or following a recipe where accuracy is key.

Quick Summary

The gram weight of a cup of Rice Krispies varies slightly depending on factors like how tightly the cereal is packed. Standard measurements and nutrition labels typically indicate a weight between 27 and 30 grams for a single cup. For the most accurate results in recipes, using a kitchen scale is the recommended method.

Key Points

Weight per cup: A cup of Rice Krispies weighs approximately 27 to 30 grams, though this can vary based on brand and how tightly it's packed.
Density is key: Because Rice Krispies are airy, their weight per cup is much lower than that of denser ingredients like granola or flour.
Accuracy matters: For baking, especially for things like Rice Krispies treats, measuring by weight with a digital kitchen scale is more precise than using a measuring cup.
Consistency in baking: Using grams ensures the proper cereal-to-marshmallow ratio, which is critical for a perfect texture.
Measurement tips: When measuring by volume, scoop the cereal loosely and level it off to get the most consistent result.

Understanding Cereal Weight and Density

The gram weight of a cup of cereal is not a universal constant, but rather depends on the product's density and how tightly it is packed. Rice Krispies, with their airy, puffed texture, weigh significantly less per cup than a denser cereal like granola or a heavier, flaked variety. This is why a cup of Rice Krispies weighs only a fraction of what a cup of sugar or flour would weigh.

Density is the key factor. The volume (the space the cereal takes up in the measuring cup) is constant, but the mass (the actual weight) changes with density. For example, a cup of sand is much heavier than a cup of feathers. This same principle applies to different types of cereal. For bakers and cooks, this means that converting from volume (cups) to weight (grams) requires knowing the specific density of the ingredient you are using.

Official and Estimated Grams per Cup

Official nutrition labels and various food databases provide slightly different numbers for the weight of a cup of Rice Krispies. While the precise number can vary due to minor differences in batch production, a commonly cited figure is between 27 and 30 grams for a 1-cup serving.

Kellogg's UK Nutrition Information: Their website lists a 30-gram serving size, which is close to a standard cup.
Sweet 2 Eat Baking: This resource provides a conversion chart listing 1 cup of Rice Krispies as weighing approximately 27 grams.
Calorie-Counting Websites: Sites like FatSecret also reference a 30-gram weight for one cup.

These minor discrepancies are why bakers and home cooks are often advised to use a digital kitchen scale for ultimate accuracy, particularly in more complex recipes like Rice Krispies Treats, where a slight variation could affect the final texture.

The Importance of Weighing for Consistency

Measuring ingredients by weight is universally considered more accurate and reliable than using volume measurements like cups. This is because weight is a fixed, absolute measurement, whereas volume can fluctuate based on how an ingredient is handled. For instance, scooping cereal directly from the box will result in a different measurement than if the cereal is packed down into the cup.

For most everyday purposes, knowing that a cup of Rice Krispies is approximately 27-30 grams is sufficient. However, for those seeking perfection in their baking, a digital scale removes all doubt. The difference in weight between a loosely filled cup and a packed cup can lead to changes in the ratio of ingredients, which can be critical for the success of a recipe.

Cereal Weight Comparison Table

To illustrate how the weight of cereal can vary, here is a comparison of the approximate gram weight for a 1-cup serving of several popular cereals:


Cereal	Approximate Grams per 1 Cup	Grams per 1/2 Cup	Grams per 1/4 Cup
Rice Krispies	27-30 g	14-15 g	7-8 g
Cheerios	28 g	14 g	7 g
Corn Flakes	28 g	14 g	7 g
Special K	45 g	23 g	11 g
Granola	50-60 g	25-30 g	12-15 g

As the table clearly shows, a cup of Special K weighs significantly more than a cup of Rice Krispies. This difference highlights the importance of recipe precision when substituting ingredients or measuring by volume instead of weight.

Practical Applications: Baking and Recipes

For recipes like the classic Rice Krispies Treats, the weight of the cereal directly impacts the final texture. If you use too much cereal by volume (i.e., a cup that is not properly measured or is over-packed), the treats might be too dry and crumbly. Conversely, using too little cereal can result in a gooey, overly soft batch. By measuring the cereal in grams, you ensure the ideal cereal-to-marshmallow ratio every time.

Here are some tips for accurate measuring:

Use a digital scale: Place a bowl on the scale and press the "tare" or "zero" button to reset the weight. Add the Rice Krispies until you reach the desired gram amount.
Measure loosely: If using a measuring cup, don't pack the cereal down. Instead, scoop the cereal and level it off with a flat edge, like a knife, to get a consistent volume measurement.
Follow the recipe: If a recipe lists ingredients by weight, always follow the gram measurement for best results.

Conclusion: Precision for a Perfect Result

In conclusion, a cup of Rice Krispies weighs approximately 27 to 30 grams, with the exact amount varying slightly by production batch and measuring technique. For standard use, a volume measurement is often fine, but for consistent and precise baking, measuring by weight with a kitchen scale is the superior method. Understanding the impact of an ingredient's density on its weight is crucial for achieving consistent results in your kitchen creations. Whether for a quick breakfast or a batch of treats, using the right measurement ensures a delicious outcome every time. You can learn more about ingredient conversions from resources like the King Arthur Baking Ingredient Weight Chart.

Frequently Asked Questions

A cup of Rice Krispies weighs so little because the cereal has a low density. The puffed rice grains are light and full of air, meaning they take up a lot of space (volume) but have very little mass (weight) compared to denser ingredients.

Yes, while a US standard cup is often used, slight variations can exist in different measuring systems. However, for dry goods like cereal, the specific density of the product is a far greater factor in its weight than regional cup size differences.

For the most accurate measurement, use a digital kitchen scale. Place a bowl on the scale, tare it to zero, and then add the cereal until it reaches the desired gram weight for your recipe.

Yes, if the Rice Krispies are crushed, their density increases. A cup of crushed Rice Krispies would weigh more than a cup of whole Rice Krispies because the air pockets would be reduced, allowing more mass to fit into the same volume.

The serving size can vary by country and package. For instance, some UK packaging references a 30-gram serving, while some US nutritional data references a 28-gram cup serving. Always check the nutrition facts on the specific box you have.

The slight variance in weight (e.g., 27g vs. 30g) is likely due to manufacturing differences, location (e.g., UK vs. US), and potential differences in how the cereal was measured for the database. Using a digital scale will provide the most consistent result for your own recipe.

Yes, other puffed or very light cereals will have a similar low weight per cup. In contrast, heavier, denser cereals like granola or dense flakes will have a much higher gram weight per cup.