How many calories in a tablespoon of sugar? A tablespoon of sugar contains 45 calories. It’s high in carbohydrates, which every healthy body needs and low in cholesterol, sodium and fat. It contains 12g carbohydrates. Cookies, cakes, candies, sweets, ready to eat cereals and soda have high sugar content. Fruits and milk products also have high sugar content. If people consume more calories than they burn, it results in weight gain. Higher calorie content results in obesity.