How long does it take to roast a chicken?

The standard UK formula is 20 minutes per 500g plus an additional 20 minutes at 180°C fan (200°C conventional / Gas Mark 6). So a 1.5kg chicken takes about 80 minutes, and a 2kg chicken about 100 minutes. Always verify with a meat thermometer — the juices should run clear and the thickest part of the thigh should read at least 75°C, the Food Standards Agency minimum for poultry.

What temperature should I roast a chicken at?

Roast at 180°C fan (200°C conventional / Gas Mark 6) — this is the temperature the standard 20 minutes per 500g plus 20 minutes formula is calibrated to. Some recipes start at a higher temperature (220°C fan) for 15-20 minutes to crisp the skin, then reduce to 180°C fan for the remainder. This high-heat start produces crispier skin but needs more attention to stop the breast drying out. Whichever method you use, the thickest part of the thigh must reach at least 75°C to be safe.

How do I get crispy chicken skin?

Pat the chicken completely dry with kitchen paper before roasting. Rub the skin with olive oil or softened butter and season generously with salt. Do not cover with foil — exposed skin crisps better. For extra crispy skin, leave the chicken uncovered in the fridge overnight before roasting, which dries the skin. Roasting on a rack (not sitting in juices) also helps.

How long should a roast chicken rest?

Rest a whole chicken for 10-20 minutes after removing from the oven, depending on size. A 1.5kg bird needs about 15 minutes. Tent loosely with foil and place on a warm plate. Do not wrap tightly or the crispy skin will go soggy from the trapped steam. Resting allows the juices to redistribute, making the meat more tender and easier to carve.

How many people does a whole chicken serve?

A standard 1.5kg chicken serves 4 people comfortably. A larger 2kg chicken serves 5-6. As a guide, allow about 400g of raw bone-in chicken per person. If you are serving with generous side dishes, you can stretch this further. For a meal with leftovers, go up a size.

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Chicken Roasting Calculator

Calculate roasting time and temperature for whole chicken by weight.

Chicken Weight

Whole chicken weight including bones

Roasting MethodChoose your preferred roasting technique

Chicken is stuffed

Stuffed birds need extra time (estimated +12 min per kg). Always check the stuffing centre also reaches 75°C — it is a food-safety hot-spot.

How We Calculate This

This calculator uses the standard UK formula for roasting chicken: 20 minutes per 500g plus 20 minutes extra, at 180°C fan (200°C conventional / Gas Mark 6). Enter the weight of your whole chicken to get the precise cooking time.

Serving estimates are based on approximately 400g of raw bone-in chicken per person. Resting time is calculated at 1 minute per 100g, with a minimum of 10 minutes and maximum of 20 minutes for chicken.

Food safety: poultry must reach at least 75°C in the thickest part of the thigh (the Food Standards Agency minimum to kill campylobacter and salmonella). Times are a guide only — always confirm with a meat thermometer, and check that the centre of any stuffing also reaches 75°C, as stuffing is a food-safety hot-spot.

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Last updated: February 2026

All calculations are based on standard ratios and conversions. Results may vary with specific ingredients, equipment, and conditions.