1) Start with the calorie reference

Use the standard nutrition baseline for raw blueberries: about 57 calories per 100 grams. That means blueberries are low in calories and a little more than 1.7 grams per calorie.

To estimate 100 calories, divide 100 by 57, then multiply by 100 grams. The result is about 175 grams. If you want a practical kitchen measure, that is roughly 1 1/4 cups, but grams are more accurate than cups.

2) Weigh your blueberries for the most accurate result

Put a bowl on a kitchen scale, tare it to zero, then add blueberries until the display reaches about 175 grams. This is the easiest way to hit 100 calories without guessing.

If you do not have a scale, use a measuring cup as a backup and expect some variation. Whole berries settle differently depending on size, moisture, and how full the cup is packed.

3) Adjust for fresh, frozen, or added ingredients

For plain raw or unsweetened frozen blueberries, the calorie count is very similar by weight. The big changes usually come from added sugar, syrup, or yogurt coatings.

If your blueberries are in a smoothie, oatmeal, or dessert, do not count only the berries. Add the calories from every ingredient if you want the total to stay near 100 calories.

4) Avoid the most common portion mistakes

A common mistake is assuming every cup of blueberries has the same calories. Cup measures can vary a lot, especially with different berry sizes.

Another mistake is using a full pint or plastic clamshell as if it were a single serving. A container often holds several 100-calorie portions, so check the weight if portion control matters.

Tips

• Use a food scale and log blueberries by grams, not by cup, for the best accuracy.
• Remember that 100 calories of blueberries is about 175 grams, not 100 grams.
• Check labels on frozen blueberries for added sugar before you estimate calories.
• If you’re building a snack, pair blueberries with protein or fat so it’s more filling.
• If you’re tracking meals by photo, Fitnit can help you estimate portions more consistently from real-world plates.