The USDA Lists the Following Recommendations for High-Altitude Adjustments

Appears in

Ingredient Adjustment 3,000 feet 914 meters 5,000 feet 1,524 meters 7,000 feet 2,134 meters
decrease baking powder per teaspoon used ⅛ teaspoon ⅛ to ¼ teaspoon ¼ teaspoon
increase liquid per cup used 1 to 2 tablespoons (15 to 30 ml) 2 to 4 tablespoons (30 to 59 ml) 3 to 4 tablespoons (44 to 59 ml)