How Many Calories in Grapefruit? Nutrition Facts & Macros
Half a grapefruit (123g) has 52 calories
Protein 0.9 g · Carbs 13.1 g · Fat 0.2 g
Grapefruit is a large citrus fruit with a distinctive bittersweet taste — a breakfast classic and longtime dieting favorite. Whether you eat it halved with a spoon, drink it as juice, or track your macros, knowing the exact nutrition facts helps. Here's everything you need to know about grapefruit calories and macros, based on USDA data. Pink grapefruit is about 88% water.
176 kJ · per 100 g · Water: 88.06 g
Calorie Calculator: Grapefruit (Pink)
123 g Grapefruit (Pink) contains 52 kcal
Calories by Portion Size
| Portion | Calories | Protein | Carbs | Fat |
|---|---|---|---|---|
| 1/2 grapefruit (123 g) | 52 kcal | 0.9 g | 13.1 g | 0.2 g |
| 1 whole grapefruit (246 g) | 103 kcal | 1.9 g | 26.2 g | 0.3 g |
| 100 grams | 42 kcal | 0.8 g | 10.7 g | 0.1 g |
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Grapefruit (Pink) — Nutrition Facts
| Grapefruit (Pink) | per 100 g |
|---|---|
| Calories | 42 kcal |
| Protein | 0.77 g |
| Fat | 0.14 g |
| Carbs | 10.66 g |
| Saturated Fat | 0.021 g |
| Monounsaturated Fat | 0.02 g |
| Polyunsaturated Fat | 0.036 g |
| Cholesterol | 0 mg |
| Fiber | 1.6 g |
| Sugar | 6.89 g |
| Sodium | 0 mg |
| Potassium | 135 mg |
| Calcium | 22 mg |
| Magnesium | 9 mg |
| Phosphorus | 18 mg |
| Iron | 0.08 mg |
| Zinc | 0.07 mg |
| Manganese | 0.022 mg |
| Selenium | 0.1 mcg |
| Vitamin A | 58 mcg |
| Vitamin C | 31.2 mg |
| Thiamine (B1) | 0.043 mg |
| Riboflavin (B2) | 0.031 mg |
| Niacin (B3) | 0.204 mg |
| Vitamin B6 | 0.053 mg |
| Folate | 13 mcg |
| Vitamin E | 0.13 mg |
| Water | 88.06 g |
Source: USDA FoodData Central (FDC ID: 174673) · Data verified September 2026
Variations
White grapefruit
33 calories per 100g — 21% fewer than pink. Less sweet, more bitter flavor. No lycopene and much less beta-carotene. Similar vitamin C content. Choose pink for more antioxidants; white if you prefer a sharper, more bitter taste.
Grapefruit juice
About 39 calories per 100g. Similar vitamins but less fiber than whole fruit. Still contains furanocoumarins that interact with medications. One glass (248g) has about 97 calories. Choose whole fruit over juice for more fiber and greater satiety.
Dietary Perspectives
For Weight Loss
Pink grapefruit has 42 kcal per 100 g. It contains 1.6 g of fiber and 88.1% water — excellent for satiety. Sugar is 6.9 g per 100 g. Half a grapefruit (~123 g, ~52 kcal) is a very filling, low-calorie breakfast item.
For Athletic Performance
Grapefruit provides 10.7 g of carbohydrates per 100 g — a light carb source. It offers 135 mg of potassium and 31.2 mg of vitamin C per 100 g. Not a primary training fuel but the hydration (88.1% water) and vitamin C content support recovery and immune function in athletes.
For Keto
Borderline for strict keto with 9.1 g of net carbs per 100 g (10.7 g total carbohydrates minus 1.6 g fiber). Half a grapefruit (~123 g) has approximately 11.2 g of net carbs — a significant portion of a daily keto budget. Small segments as a flavor accent can fit, but eating a full half is too high for most keto protocols. Lemon (6.5 g net carbs / 100 g) is a safer citrus option.
Frequently Asked Questions
How many calories are in grapefruit?
Half a grapefruit (123g) has approximately 52 calories. Per 100g, pink grapefruit has 42 calories. A whole grapefruit (246g) has about 103 calories. White grapefruit has fewer calories at 33 kcal per 100g. 42 kcal per 100 g for such a filling fruit.
How much vitamin C is in grapefruit?
Pink grapefruit has 31.2mg of vitamin C per 100g. Half a grapefruit (123g) provides about 38mg — roughly 42% of the daily recommended intake. While less than oranges (53mg per 100g), grapefruit is still an excellent vitamin C source with fewer calories.
Does grapefruit have lycopene?
Yes, pink and red grapefruit contain 1419 mcg of lycopene per 100g — the same antioxidant found in tomatoes. Lycopene gives pink grapefruit its color and is linked to heart health. White grapefruit has virtually no lycopene. Half a pink grapefruit provides about 1745 mcg of lycopene.
Can grapefruit interact with medications?
Yes — this is important. Grapefruit contains furanocoumarins that block the CYP3A4 enzyme in your intestines, affecting how certain medications are metabolized. This can increase drug levels to potentially dangerous amounts. Affected medications include: some statins (atorvastatin, simvastatin), calcium channel blockers, some anti-anxiety drugs, and immunosuppressants. Always consult your doctor if you take medications regularly.
How much sugar is in grapefruit?
Pink grapefruit has 6.89g of sugar per 100g. Half a grapefruit (123g) has about 8.5g of sugar. This is less than oranges (9.35g per 100g), apples (10.39g), and grapes (15.48g). The bittersweet taste means less perceived sweetness despite moderate sugar content.
Is grapefruit good for weight loss?
Grapefruit is excellent for weight loss at just 42 kcal per 100g. Half a grapefruit (52 kcal) is filling due to its water content (88%) and fiber (1.6g per 100g). Some studies suggest grapefruit may help with insulin sensitivity. The “grapefruit diet” is extreme, but including grapefruit as part of a balanced diet is beneficial. Eat the whole fruit rather than juice for more fiber and fewer calories.
Compare with Similar Foods
| Portion | kcal | Protein | Carbs | Fat |
|---|---|---|---|---|
| Grapefruit (Pink) | 42 | 0.77 g | 10.66 g | 0.14 g |
| Orange | 47 | 0.94 g | 11.75 g | 0.12 g |
| Mandarin Orange | 53 | 0.81 g | 13.34 g | 0.31 g |
| Clementine | 47 | 0.85 g | 12.02 g | 0.15 g |
| Lemon | 29 | 1.1 g | 9.32 g | 0.3 g |
per 100 g
Half a grapefruit has just 52 kcal (123g) with vitamin C, lycopene, and only 8.5g of sugar. Pink grapefruit has 42 kcal per 100g — among the lowest-calorie citrus fruits.
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