The United States Department of Agriculture provides a database of many common foods that can be searched by nutrient, including carbohydrates. Each individual food page also lists the carbohydrate amount.
The USDA database is searched by food groups, subsets of food and up to three different nutrients at a time. The servings are measured by household or by 100 grams.
According to SFGate, since not all carbohydrates are created equally, determining a healthy amount of carbohydrates from food labels requires additional thinking. Facts such as the dietary fiber, net carbohydrates, sugars and the ingredient list may tell a different story than the basic carbohydrate count.