A four-quart slow cooker is large enough to feed a family of four to five people without leftovers. A larger slow cooker, five quarts or higher, is ideal for those who want to have some food left over.
The choice between a four- or five-quart slow cooker depends on the needs of your household. Slow cookers are helpful for large families with busy schedules, since they often enable the family to make enough food for both dinner and the next day's lunch. For further ease of use, there are programmable options that allow automatic shutoff and warming over prolonged periods of time.