You want to find out how many calories in Grapefruit. This is the right place!
Grapefruit has 38 kilocalories on average, with as low as 30 kilocalories and as high as 60 kilocalories per 100 grams.
You can spend these 38 kilocalories: swimming for 3 minutes!
While wondering how many calories in Grapefruit is fine, regular excercise and a balanced diet are habits that build a healthy life, and low calorie intake cannot substitute that.
Start caring about your health: Find about your ideal weight but stay away from diets that promise great weight loss in a short amount of time.
Data source: the credible USDA National Nutrient Database for Standard Reference.