To convert an oven temperature from Fahrenheit to Celsius, subtract 32 and multiply by 5/9. To convert Celsius to Fahrenheit, multiply by 9/5 and add 32. For example, 350°F is about 177°C, commonly rounded to a 175°C or 180°C oven setting. Fan-assisted and conventional oven settings are a separate issue: follow the recipe and appliance guidance rather than treating unit conversion as a fan adjustment.