There are 11 calories in a cup of mixed salad greens with carrots and tomatoes, according to FatSecret. Eight percent of those calories come from fat, 74 percent from carbohydrates and 18 percent from protein.
The darker the salad greens, the more nutrients the salad has, although calorie count is not increased. A mix of colorful vegetables also increases the nutritional value without significantly increasing added calories. There are different mixes of vitamins and minerals in different colored vegetables, so a colorful salad is more nutritious than one that is all green. Fitness magazine cautions about overdoing other salad add-ins. Meats and beans add significantly more calories to a salad, as do cheese and nuts. Salad dressing is also usually very high in calories.