How much sugar is in grapefruit?
Grapefruit has 8.5 g of sugar per 1/2 medium (123 g) — about 2 teaspoons. That's 6.9 g per 100 g, and it's all naturally occurring — whole grapefruit has no added sugar.
USDA FoodData Central · raw · FDC 174673
Sugar by portion
| Portion | Sugar | ≈ teaspoons | Total carbs | Calories |
|---|---|---|---|---|
| 1/2 medium (123 g) | 8.5 g | 2 tsp | 13.2 g | 52 |
| 100 g | 6.9 g | 1.6 tsp | 10.7 g | 42 |
| 1 oz (28 g) | 2 g | 0.5 tsp | 3 g | 12 |
Teaspoon figure converts grams of sugar at ~4.2 g per level teaspoon, for scale only. This is the total sugar naturally present — whole grapefruit carries no added sugar. Values from USDA per-100 g data (FDC 174673, SR Legacy). raw.
Half a medium grapefruit has about 8.5 g of sugar — roughly 2 teaspoons — in a 123 g serving, or 6.9 g per 100 g. That puts grapefruit among the lower-sugar citrus options, noticeably less sweet than an orange and a long way from grapes or cherries. Its slightly tart, bitter edge is the giveaway, and it’s a big part of why grapefruit became the classic “diet” fruit. Just as important: that 8.5 g is all naturally occurring sugar, with no added sugar anywhere in a bowl of fresh grapefruit.
Natural sugar, not added sugar
The sugar in grapefruit comes bundled the way whole fruit always delivers it — with about 2 g of fiber, plenty of water, and a generous hit of vitamin C. That package is what makes naturally occurring fruit sugar different from the added sugar in soda, juice drinks or candy. Added sugar is the kind health guidance asks you to limit; the sugar inside a fresh grapefruit isn’t that, even though the label-style number looks the same. If you ever pick up packaged or canned grapefruit, that’s where to look closely — fruit canned in syrup or sweetened juice can carry real added sugar, while the whole fresh fruit has none.
A naturally lighter pick
Grapefruit’s appeal for anyone watching sugar, calories or weight is straightforward: it’s relatively low-sugar, low-calorie, tart, and filling for what it is. Half a fruit at ~8.5 g of sugar and about 52 calories is an easy, sensible serving. That said, it’s worth flagging one thing that has nothing to do with sugar: grapefruit can interact with certain medications by changing how the body processes them, so if you take prescription drugs it’s genuinely worth a quick word with your pharmacist or doctor. That’s a neutral heads-up, not advice for or against eating it. And for diabetes or weight goals specifically, your own clinician or dietitian is the right person to set your numbers — this page is general information only.
Bottom line: grapefruit is a tart, vitamin-C-rich, naturally lower-sugar fruit, with the medication note as the only real asterisk. For the rest of the nutrition picture, see protein in grapefruit — and for anything packaged or canned, always read the label’s own sugar and added-sugar lines.
Frequently Asked Questions
How much sugar is in half a grapefruit?
About 8.5 g of sugar in half a medium grapefruit (123 g), which is 6.9 g per 100 g (USDA FDC 174673). That half is roughly 52 calories and 13.2 g of total carbohydrate, with about 2 g of fiber. A whole medium grapefruit is double that — close to 17 g of sugar.
How many teaspoons of sugar is that?
A little over 2 teaspoons. We convert the 8.5 g of sugar in half a grapefruit at about 4.2 g per level teaspoon, just to make the amount easy to picture. It's a scale for your head, not a sign sugar was added — grapefruit grows with its sugar already inside.
Is the sugar in grapefruit natural or added?
All natural. Whole grapefruit has no added sugar — every gram is the fruit's own, delivered with fiber, water and a big dose of vitamin C. That's a different package from the added sugar in soda or sweets, which is the kind dietary guidance tells you to cut back on. Grapefruit simply doesn't have an added-sugar line.
Is grapefruit good if I'm watching sugar or weight?
It's one of the lower-sugar, lower-calorie fruits, which is why it has a long reputation as a 'diet' food. Half a medium grapefruit is about 8.5 g of sugar and roughly 52 calories, with around 2 g of fiber — a light, tart choice. Many people managing weight or blood sugar like it for exactly that reason, but this is general information, not medical advice. Note also that grapefruit can interact with certain medications, so if you take prescription drugs it's worth a quick check with your pharmacist or doctor.
How much sugar is in a whole grapefruit?
A whole medium grapefruit (about 246 g) has roughly 17 g of sugar — double the half-fruit serving — for around 105 calories. It's still a relatively low-sugar fruit per gram; you're just eating twice as much of it.
When was this data last verified?
2026-06-04, against USDA FoodData Central FDC 174673 (Grapefruit, raw, pink and red, all areas; SR Legacy). We re-verify reference pages periodically and update when the underlying USDA entry changes.
Whole-food values are USDA reference data, not a Labelgrade (that score is for branded packaged products, where we penalize added sugar). See our methodology and the added-sugar calculator.