Cooking Time Reference Chart
Use the calculator above for exact times based on your specific weight, or refer to this general guide for cooking times per kilogram. All times assume the meat is fully thawed and at room temperature before going in the oven.
| Meat |
Oven Temp |
Time per kg |
Rest Time |
| Turkey (whole) | 180°C / Gas 4 | 40 min/kg + 20 min | 30 min |
| Turkey Crown | 190°C / Gas 5 | 40 min/kg + 20 min | 20 min |
| Whole Chicken | 200°C / Gas 6 | 45 min/kg + 20 min | 15 min |
| Beef (medium) | 180°C / Gas 4 | 25 min/kg + 25 min | 20 min |
| Lamb (medium) | 180°C / Gas 4 | 25 min/kg + 25 min | 20 min |
| Pork | 180°C / Gas 4 | 35 min/kg + 30 min | 20 min |
| Gammon | 180°C / Gas 4 | 30 min/kg + 30 min | 15 min |
How to Get a Perfect Roast Every Time
Bring the meat to room temperature
Take your roast out of the fridge 30-60 minutes before cooking (longer for larger joints). Cooking cold meat straight from the fridge means the outside will overcook before the centre is done. This single step is the most common mistake home cooks make.
Use a meat thermometer
The most reliable way to check if a roast is done is with an instant-read meat thermometer. Stick it into the thickest part of the meat, avoiding bone. Target internal temperatures: chicken and turkey 75°C, beef rare 50°C / medium 60°C / well done 70°C, lamb medium 60°C, pork 70°C, gammon 70°C.
Always rest your meat
When meat cooks, the juices migrate to the centre. Resting lets them redistribute throughout the meat, so when you carve it, the juices stay in the meat instead of pouring out onto the chopping board. Rest small joints (chicken) for 10-15 minutes, larger joints (turkey, big beef roasts) for 20-30 minutes. Cover loosely with foil to keep warm.
Trust the calculator, not the clock
Cooking times are estimates — every oven is different, every joint of meat is slightly different in shape. Always start checking 15-20 minutes before the calculated end time, especially for smaller cuts. A meat thermometer is more accurate than any timer.
Frequently Asked Questions
How long do you cook a turkey per kg?
For a whole turkey, cook for 40 minutes per kilogram at 180°C (gas mark 4), plus an extra 20 minutes. So a 5kg turkey takes about 3 hours 40 minutes total. Always rest for at least 30 minutes before carving. Use a meat thermometer to confirm the internal temperature reaches 75°C in the thickest part of the breast.
How long to cook a roast beef?
Roast beef cooking time depends on how well done you want it. At 180°C (gas mark 4): for rare, cook for 20 minutes per kg + 20 minutes; for medium, 25 minutes per kg + 25 minutes; for well done, 30 minutes per kg + 30 minutes. Always rest for at least 20 minutes before carving.
How long does a turkey crown take to cook?
A turkey crown cooks faster than a whole turkey because there are no legs or cavity to slow down heat penetration. Cook at 190°C (gas mark 5) for 40 minutes per kilogram plus 20 minutes. A 2.5kg turkey crown takes about 2 hours. Rest for 20 minutes before carving.
How long to cook a leg of lamb?
For a leg of lamb at 180°C (gas mark 4): rare needs 20 minutes per kg + 20 minutes; medium needs 25 minutes per kg + 25 minutes; well done needs 30 minutes per kg + 30 minutes. A 2kg leg of lamb (medium) takes about 1 hour 15 minutes. Always rest for 20 minutes before carving.
How long to cook a roast chicken?
Roast a whole chicken at 200°C (gas mark 6) for 45 minutes per kilogram, plus 20 minutes. A standard 1.5kg chicken takes about 1 hour 30 minutes. The chicken is cooked when the juices run clear from the thickest part of the thigh, or when an instant-read thermometer shows 75°C. Rest for 15 minutes before carving.
How long does pork take to cook per kg?
Roast pork takes 35 minutes per kilogram at 180°C (gas mark 4), plus an extra 30 minutes. A 1.5kg pork joint takes about 1 hour 20 minutes. For crackling, increase the heat to 220°C (gas mark 7) for the first 30 minutes, then reduce to 180°C for the remaining time. Pork should reach an internal temperature of 70°C.
How long to cook gammon per kg?
Gammon takes about 30 minutes per kilogram at 180°C (gas mark 4), plus 30 minutes. A 2kg gammon joint takes about 1 hour 30 minutes. Many cooks boil gammon first for the same time, then finish in the oven with a glaze for the last 20-30 minutes. Always check the packaging — some gammons need soaking overnight to remove excess salt.
Why do I need to rest meat after cooking?
Resting allows the muscle fibres to relax and reabsorb the juices that have been pushed to the centre during cooking. Without resting, those juices spill out the moment you cut into the meat, leaving it dry. Resting also makes carving much easier because the meat firms up slightly. As a rule, larger joints need longer rest times — 10-15 minutes for chicken, 20-30 minutes for turkey or large beef joints.
What's the best oven temperature for roasting?
For most roasts, 180°C (gas mark 4) is the sweet spot — hot enough to brown the outside but gentle enough to cook the inside evenly without drying it out. Chicken and turkey crown benefit from slightly higher heat (190-200°C / gas mark 5-6) for crisper skin. For pork crackling or beef searing, start at 220°C (gas mark 7) for 20-30 minutes then reduce to 180°C.