One cup of raw blueberries contains about 84 calories, making them one of the lowest-calorie fruits you can eat. A smaller 100-gram serving (about 3.5 ounces, or two-thirds of a cup) comes in at just 57 calories. Whether you’re tracking calories or just curious, blueberries are remarkably light for how filling and flavorful they are.
Calories by Serving Size
The calorie count shifts depending on how much you’re eating and how the blueberries are prepared. Here’s how the most common portions compare:
- 1/3 cup fresh (about 50g): roughly 28 calories
- 3.5 oz / 100g fresh: 57 calories
- 1 cup fresh or frozen (about 148g): 80 to 84 calories
- 1 cup dried: over 500 calories
Fresh and frozen blueberries are nutritionally almost identical. Frozen berries are typically flash-frozen right after harvest, so they retain their nutrients and calorie profile. Dried blueberries, on the other hand, are a completely different story. Removing the water concentrates everything: one cup of dried blueberries packs more than six times the calories and roughly 100 grams of sugar compared to 15 grams in a fresh cup. If you’re snacking on dried blueberries, keep portions closer to a quarter cup.
Carbs, Sugar, and Fiber Breakdown
Most of the calories in blueberries come from carbohydrates. One cup of fresh blueberries contains about 21 grams of total carbs, with roughly 14 to 15 grams of natural sugar and 3.5 grams of dietary fiber. That leaves about 17 to 18 grams of net carbs per cup. Protein and fat are minimal, at less than 1 gram each.
The fiber content is worth noting because it slows down how quickly those natural sugars hit your bloodstream. Blueberries have a glycemic index of 40, which falls in the low range. For comparison, anything under 55 is considered low glycemic. This means blueberries cause a relatively gentle rise in blood sugar compared to higher-sugar fruits like watermelon or pineapple, making them a solid choice if you’re managing blood sugar levels.
Key Vitamins and Minerals
Blueberries aren’t just low in calories. One cup provides 29 micrograms of vitamin K, which plays a role in blood clotting and bone health. You also get about 2 milligrams of vitamin C and half a milligram of manganese, a mineral involved in metabolism and bone formation. These aren’t blockbuster amounts on their own, but they add up as part of a varied diet.
The real nutritional standout is the anthocyanins, the pigments responsible for that deep purple-blue color. These plant compounds act as antioxidants in the body, and blueberries are one of the richest everyday sources. You don’t need to eat large quantities to benefit. Even a third of a cup per day is associated with measurable health benefits.
Wild vs. Store-Bought Blueberries
Calorie-wise, wild and cultivated blueberries are similar. Both hover around 80 to 84 calories per cup. The meaningful difference is in antioxidant concentration. Wild blueberries are smaller, so you get more skin per berry in every handful, and the skin is where the anthocyanins are concentrated. Wild varieties pack noticeably more of these compounds into the same serving size. If you can find them (they’re often sold frozen), they’re a particularly nutrient-dense option for the same calorie cost.
How Blueberries Compare to Other Fruits
At 57 calories per 100 grams, blueberries sit in the lower range among popular fruits. Strawberries are slightly lower at about 32 calories per 100 grams, while bananas come in around 89 and grapes at about 67. Blueberries offer a better fiber-to-sugar ratio than grapes and a lower glycemic impact than bananas, which makes them a particularly good option if you want something sweet without a big calorie or blood sugar hit.
One cup is the standard recommended serving for fresh or frozen blueberries, and at under 85 calories, it’s easy to fit into almost any eating plan. Toss them on oatmeal, blend them into a smoothie, or eat them straight from the container. The calorie count stays low as long as you stick with fresh or frozen and watch your portions with dried varieties.