RoastTime is a free cooking time calculator that tells you exactly how long to roast turkey, beef, chicken, lamb, pork, and gammon based on the weight of your joint. No more Googling "how long to cook a 2kg chicken" every Christmas — just enter the weight and get the answer.
The cooking times are based on widely accepted guidelines from trusted sources including BBC Good Food, the Food Standards Agency, and professional chef recommendations. Times are calculated per kilogram (or pound) with a base time added, and adjusted for doneness (rare, medium, well done) where applicable.
The calculator also shows the correct oven temperature and gas mark, plus a recommended resting time — because resting is the most overlooked step in getting a perfect roast.
The fan oven toggle reduces the cooking temperature by 20°C and the cooking time by approximately 10%, which is the standard adjustment recommended by oven manufacturers. Every oven is slightly different, so always use a meat thermometer to verify your roast is cooked through, especially for poultry.
These are guidelines, not guarantees. Every oven behaves differently, and the shape of the joint affects cooking time as much as the weight. Always use a meat thermometer for food safety — poultry should reach 75°C internal temperature, and pork should reach 70°C. When in doubt, cook for longer rather than shorter.
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