How Long to Cook a 2.5kg Chicken

Q: How long to cook a 2.5kg chicken?

A 2.5 kg chicken takes about 2 hr at 180°C fan, to an internal temperature of 74°C.

Cooking Times for a 2.5kg Chicken

Weight	Cooking time	Internal temp
2.5 kg	2 hr	74°C

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Other Weights

How This Calculator Works — Formula & Method

Source: standard UK roasting guidance · applied deterministically · verify with a thermometer

Constant	Value	Source
Min per 500 g	20 min (range 18–22)	UK roasting guides
Internal target	74°C / 165°F	FSA / thermometer
Base offset	20 min	Standard
Oven	180°C fan	Method
Resting	15 min	Best practice

— Chicken cooking time —
total_min = min_per_500g × (weight_g / 500) + base_offset
range = [lo_per_500g … hi_per_500g] × (weight_g / 500) + base_offset
conventional_oven = fan_temp + 10–20°C (same time)
fahrenheit = derived table from °C
— algorithm —
lookup(meat, cut, doneness) → point_estimate → guidance_range
→ internal_target_temp → verify_with_thermometer()

Public roasting guidance applied deterministically — this is not a food-safety authority. Always cook to the stated internal temperature, measured with a meat thermometer.

Frequently Asked Questions

A 2.5 kg chicken takes about 2 hr at 180°C fan, to an internal temperature of 74°C.

Roast at 180°C fan (200°C conventional / 375°F). Roast at 180°C fan. Juices must run clear and the thickest part reach 74°C. Rest 15 min.