Adjusting cooking times and temperatures is a matter of math and vigilance. Conversion works best for heartier dishes like meat, pork or poultry or a tuna casserole. Delicate dishes that involve an exact amount of ingredients even before cooking, such as a cake or bread, should not be rushed. Conversion methods also work best at sea-level or lower altitudes, but well below 5,000 feet.
- Oven; Thermometer; Kitchen Timer; Calculator
Divide 475 by 400 to reach the mathematical representation of how much more heat is being used, or 1.1875. In general, divide the desired temperature by the recipe temperature.
Divide 60 by 1.1875 to reach a new cooking time of 50.52 minutes at 475 degrees F.
Be vigilant. The make or age of the oven may cause cooking time to vary, so keep an eye on the dish. For example, a conventional oven and a convection oven will require different cooking times and temperatures.
Use a kitchen timer to make sure you do not burn the dish at the new temperature.
Check the temperature of the meat when done to make sure it has reached a safe temperature according to the U.S. Department of Agriculture.