A medium orange (about 131 grams) contains roughly 62 to 66 calories, depending on the exact size. That makes oranges one of the lowest-calorie fruits you can grab as a snack, with most of those calories coming from natural sugars and a solid dose of fiber.
Calories by Size and Variety
Orange calories scale predictably with size. A small orange (around 100 grams) has close to 47 calories. A medium one lands in the 62 to 66 range. A large orange can reach 80 calories or slightly more. If you’re tracking calories closely, weighing the fruit matters more than eyeballing it.
Different varieties are surprisingly similar. A medium navel orange (154 grams) has about 80 calories, while a blood orange of the same weight comes in around 70. Mandarins and clementines are smaller, so they tend to fall in the 35 to 47 calorie range per fruit, but that’s mostly because you’re eating less fruit, not because the calorie density is meaningfully different.
What Else Is in That Orange
A medium orange packs about 24.7 grams of total carbohydrates, with 18.2 grams of that coming from natural sugars and 3.9 grams from dietary fiber. There’s almost no fat or protein to speak of. The fiber is worth paying attention to: it slows sugar absorption and keeps you full longer. In satiety research, oranges ranked twice as filling as white bread, calorie for calorie, largely because of their fiber and water content.
Oranges are also one of the best everyday sources of vitamin C. A single medium orange delivers more than the daily recommended amount. You’ll also get a meaningful amount of potassium, folate, and smaller quantities of calcium and B vitamins.
Why Oranges Are Easy on Blood Sugar
Despite containing 18 grams of sugar, a whole orange has a glycemic index of just 42, which is considered low. The glycemic load, a more practical measure of how a food actually affects your blood sugar in a real serving, is only 5. For context, anything under 10 is considered low. The fiber, water, and cell structure of the fruit all slow down how quickly sugar enters your bloodstream. This is one reason whole fruit behaves very differently in your body than the same amount of sugar from candy or soda.
Whole Oranges vs. Orange Juice
An 8-ounce glass of orange juice has roughly 110 to 120 calories, nearly double what you’d get from eating a whole orange. The sugar content per cup is comparable between juice and fresh segments, but the fiber difference is dramatic: a cup of orange segments contains 4.3 grams of fiber, while a cup of juice has less than 1 gram.
That missing fiber changes the experience in two ways. First, juice is far less filling. You can drink 120 calories of orange juice in seconds and still feel hungry, while peeling and eating a whole orange takes time and leaves you more satisfied. Second, without fiber to slow things down, the sugar in juice hits your bloodstream faster. If you’re choosing between the two for a snack, the whole fruit wins on every nutritional metric except convenience.
Oranges as a Weight-Friendly Snack
At roughly 65 calories with nearly 4 grams of fiber, oranges are unusually filling for their calorie cost. The high water content (about 87% of the fruit’s weight) adds volume to your stomach without adding calories. Research on satiety found that oranges and apples were the most filling common fruits tested, outperforming many foods with significantly higher calorie counts.
If you’re snacking on an orange instead of a granola bar (which typically runs 150 to 250 calories with less fiber), you’re cutting calories while likely feeling just as satisfied. The natural sugar provides quick energy, and the fiber prevents the crash that comes from more processed snacks.