Here I got a conversion chart of cooking temperature for reference or guide...
As a rule of thumb Celsius is roughly half the Fahrenheit temperature.
Fan assisted ovens are usually set approximately 25 degrees Celsius (i.e. approximately 50 degrees Fahrenheit) lower than others and cooking time is reduced by 10 minutes for every hour of cooking time.
Fahrenheit Celcius Gas Mark Desription
225 110 1/4 Very slow
250 120/130 1/2 Very slow
275 140 1 Slow
300 150 2 Slow
325 160/170 3 Moderate
350 180 4 Moderate
375 190 5 Moderately hot
400 200 6 Moderately hot
425 220 7 Hot
450 230 8 Hot
475 240 9 Very hot
Different manufacturers and oven types do vary, so always refer to your cooker instruction book.