The ideal refrigerator temperature is between 35-40 degrees F (1.8-4 C). This range slows the growth of bacteria without risk of freezing foods.
The temperature range that the refrigerator will maintain will vary by product. In general, the fresh food section will cool to an average temperature between 34 and 41 degrees F, and the freezer temperature will average between -10 and 20 degrees F.
Generally, you want to start with the temperature setting in the middle position and allow the refrigerator to stay that way for at least 3 days. After three days, adjust the setting to a higher or lower number to suit your preference. Allow the unit to stabilize one day before making another change.