How many carbs are in blueberries?
Blueberries has 21.5 g of total carbs per 1 cup (148 g) — about 17.9 g net carbs after 3.6 g of fiber. That's 14.5 g of carbs per 100 g, roughly 8% of the 275 g Daily Value.
USDA FoodData Central · raw · FDC 171711
Carbs by portion
| Portion | Total carbs | Net carbs | Fiber | Sugar | Calories |
|---|---|---|---|---|---|
| 1 cup (148 g) | 21.5 g | 17.9 g | 3.6 g | 14.8 g | 84 |
| 100 g | 14.5 g | 12.1 g | 2.4 g | 10 g | 57 |
| 1 oz (28 g) | 4.1 g | 3.4 g | 0.7 g | 2.8 g | 16 |
Net carbs = total carbs − fiber (the carbs that raise blood sugar, used in keto/low-carb tracking). Values computed from USDA per-100 g data (FDC 171711, SR Legacy). raw.
Blueberries get the “superfood” halo, but a full cup is still a real serving of carbohydrate. One cup (148 g) carries about 21 g of total carbs, of which roughly 15 g is sugar, at 14.5 g of carbs per 100 g. There’s almost no fat and under a gram of protein, so blueberries are essentially natural sugar, fiber and antioxidants. When you ask “how many carbs in blueberries,” the answer is: moderate per cup, and most of it is sugar — the antioxidants don’t change the carb math.
Net carbs and the portion that fits low-carb
For keto, low-carb and blood-sugar tracking, the number that counts is net carbs — total carbs minus fiber. A cup of blueberries has about 4 g of fiber, so it nets out near 18 g net carbs. That’s high for a strict keto budget (20–50 g net a day), but blueberries scale down well: per 100 g they’re about 12 g net, and a quarter-cup lands near 4–5 g net — a genuinely keto-sized portion. So blueberries are not keto by the cupful, but very workable in smaller handfuls, and they’re one of the friendlier fruits for low-carb eating overall.
Natural sugar, and lower-glycemic than a banana
The distinction to keep straight: the ~15 g of sugar in a cup of blueberries is intrinsic fruit sugar, not added sugar. It comes bound up with fiber and the polyphenols the berry is famous for, and that whole-food matrix is why blueberries have a relatively gentle glycemic load — generally lower than a ripe banana, which carries more sugar with less fiber to slow it down. None of that makes blueberries sugar-free; “antioxidant-rich” and “sugary” are both true at once. But among sweet fruits, a sensible portion of blueberries is one of the kinder choices for blood sugar — which is exactly why they’re a staple even on careful, lower-carb plans.
If you want the protein side of the picture, see protein in blueberries — and for packaged blueberry products (dried, muffins, jam), always read the label’s own carb and added-sugar lines, since those numbers can look nothing like the fresh berry.
Frequently Asked Questions
How many carbs are in a cup of blueberries?
About 21 g of total carbohydrate in a 1-cup serving of blueberries (148 g), which is 14.5 g per 100 g (USDA FDC 171711). They're often called a 'superfood,' but a full cup is still a meaningful dose of carbs — most of it natural sugar.
How much sugar is in blueberries?
Roughly 15 g of sugar in a cup of blueberries (10 g per 100 g, USDA FDC 171711). It's natural fruit sugar packaged with fiber and antioxidants — different from added sugar, though it still counts toward your daily total.
What are the net carbs in blueberries?
About 18 g net carbs per cup — total carbs (21 g) minus roughly 4 g of fiber. Per 100 g that's about 12 g net, so a smaller handful (say a half-cup) lands near 9 g net and fits low-carb plans more comfortably.
Are blueberries keto or low-carb?
A full cup isn't strictly keto at ~18 g net carbs, but blueberries are among the more keto-friendly fruits in smaller amounts. A quarter-cup (~4–5 g net) is a common keto-sized portion; berries generally beat banana, apple and grapes for low-carb eating.
Are blueberries lower-glycemic than a banana?
Generally yes. Blueberries carry more fiber relative to their sugar and have a lower glycemic load per typical serving than a ripe banana, so they tend to raise blood sugar more gently. They're still sugary — 'antioxidant-rich' doesn't mean sugar-free — but among sweet fruits they're a relatively gentle choice, especially in a sensible portion.
When was this data last verified?
2026-06-04, against USDA FoodData Central FDC 171711 (Blueberries, raw; SR Legacy). We re-verify reference pages periodically.
Whole-food values are USDA reference data, not a Labelgrade (that score is for branded packaged products). See our methodology and the macro calculator to turn this into a daily target.