How long does it take to roast a chicken?

The standard formula is 20 minutes per 500g plus an additional 20 minutes at 170°C fan (190°C conventional). 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 75°C.

What temperature should I roast a chicken at?

Roast at 170°C fan (190°C conventional / Gas Mark 5). Some recipes start at a higher temperature (220°C) for 15-20 minutes to crisp the skin, then reduce to 170°C for the remainder. This high-heat start method produces a crispier skin but requires more attention to prevent the breast drying out.

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.

BakeCalcs

Chicken Roasting Calculator

Calculate roasting time and temperature for whole chicken by weight.

Chicken Weight

Whole chicken weight including bones

How We Calculate This

This calculator uses the standard UK formula for roasting chicken: 20 minutes per 500g plus 20 minutes extra, at 170°C fan (190°C conventional). 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.

Frequently Asked Questions

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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.