The number of calories in a cucumber varies depending on its size and how it is measured:

• A whole cucumber about 8 to 11 inches long (around 300 grams) contains approximately 45 calories

• One cup of sliced cucumber (about 104 grams) has around 16 to 19 calories

• A half-cup serving (52 grams) provides about 8 calories

• A medium cucumber (about 18 cm long) has roughly 24 calories

• An English cucumber is often counted as about 30 calories for the entire cucumber

Overall, cucumbers are very low in calories, mostly due to their high water content (about 95-96%) and minimal fat. Eating cucumbers with the peel maximizes their nutrient and fiber content