A single medium stick of celery (7.5 to 8 inches long) contains roughly 6 calories. That makes it one of the lowest-calorie whole foods you can eat, and the reason is simple: celery is about 95% water.
Calories by Size and Serving
The FDA lists a standard serving of celery as two medium stalks, weighing about 110 grams combined. That full serving has zero fat, zero protein, 2 grams of fiber, and 2 grams of natural sugar. Total calories for those two stalks come to roughly 11. A smaller stalk (6 inches) will run you about 3 to 4 calories, while a large stalk from the outer ribs of the bunch, closer to 11 or 12 inches, lands around 9 to 10.
For context, you could eat an entire head of celery and still take in fewer calories than a single banana.
Is Celery Really a “Negative Calorie” Food?
The popular claim is that your body burns more calories digesting celery than celery actually contains. Researchers put this to the test by feeding celery to bearded dragons (chosen because their digestive process can be precisely measured in a lab setting) and tracking every bit of energy that went in and came out. The lizards lost about 29% of the meal’s energy through waste, another 14% through other excretion, and 33% to the energy cost of digestion itself. But they still retained about 24% of the calories from the celery.
Separate data on humans found that chewing 100 grams of raw celery (about four stalks) takes roughly five minutes and around 400 chews, burning only about 4 extra kilojoules in the process. That’s a tiny fraction of the energy in the celery itself. So while celery is extraordinarily low in calories, it is not truly “negative calorie.” You do gain a small amount of net energy from eating it.
What Else Is in That Stick
Celery’s calorie count is almost irrelevant compared to what it delivers in other ways. It’s a significant source of vitamin K, provides potassium, and contains meaningful levels of two plant compounds called apigenin and luteolin. These are flavones, a type of antioxidant, and celery ranks among the top vegetable sources of both. USDA data places celery’s flavone concentration between 10 and 50 milligrams per 100 grams, which is a relatively high range for a common vegetable.
Celery also contains a compound that promotes the production of nitric oxide in blood vessel walls, which helps them relax and widen. This is the same basic mechanism behind many blood pressure treatments, though in celery the effect is far milder. It’s one reason celery has been used in traditional medicine for cardiovascular support, even if eating a few stalks won’t replace actual treatment.
Hydration in Disguise
Because celery is roughly 95% water by weight, eating it contributes to your daily fluid intake in a real way. About 20% of the fluid most people take in each day comes from food rather than drinks. Two stalks of celery deliver close to 100 grams of water alongside 2 grams of fiber, making it both hydrating and filling relative to its calorie count.
Raw vs. Cooked
Raw celery retains slightly more antioxidants, but cooking makes certain other nutrients easier to absorb and can be gentler on your digestive system. Steaming is the best middle ground: it preserves most of the nutritional value while softening the tough fibers. Cooking doesn’t meaningfully change the calorie count since the calories come from small amounts of sugar and fiber that survive heat.
If you’re adding celery to soups or stir-fries, the calorie difference between raw and cooked is negligible. What changes more dramatically is what you pair it with. A tablespoon of peanut butter on a celery stick adds about 95 calories, turning a 6-calorie snack into a 100-calorie one. That’s still a perfectly reasonable snack, but it’s worth knowing where the calories are actually coming from.