Weights And Measures

Conversions
Some useful conversions for your cooking recipes. Also check out this handy Online Cooking Converter.

Oven Temperatures
Gas mark 1 is 275° fahrenheit (135° celsius). Oven temperatures increase by 25°F (13.9°C) each time the gas mark increases by 1.
Below gas mark 1 the scale markings halve at each step, each representing a decrease of 25°F.
Fan-Assisted ovens should be set about 20°C cooler than conventional ones for the same roasting results.
Conversion table
Gas mark Fahrenheit Celsius Descriptive
1/4 225° 107° Very Slow/Very Low
1/2 250° 121° Very Slow/Very Low
1 275° 135° Slow/Low
2 300° 149° Slow/Low
3 325° 163° Moderately Slow/Warm
4 350° 177° Moderate/Medium
5 375° 191° Moderate/Moderately Hot
6 400° 204° Moderately Hot
7 425° 218° Hot
8 450° 232° Hot/Very Hot
9 475° 246° Very Hot
Though apparently your Gas Mark mileage may vary!
Invest in an oven thermometer.