How many calories in a cup of strawberries? The calories in a cup of strawberries depend on how the fruit is consumed. A cup of whole strawberries contains 46 calories whereas a cup of halved strawberries contains 49 calories and a cup of sliced strawberries contains 53 calories. Strawberries have 1% fat, 6% potassium 4% carbohydrates 2% protein, dietary fiber 12%, 141% Vitamin C, 2% Calcium, phosphorous 4%, magnesium 5%, zinc 1% and 3% Iron. They contain more vitamin C than other citrus fruits.