How much turkey do I need? A size and timing guide

It is the question we are asked more than any other between the middle of November and Christmas Eve, usually across the counter with a bit of arithmetic going on in the background. Nine for lunch, two of them children, one of them a nephew who eats like a Labrador, and somebody wants sandwiches on Boxing Day. Four kilos or six? Here is how we work it out, and how you can too.

The short answer: how much turkey per person

For a whole bird on the bone, allow 400g to 500g per person. That is the figure to use if you want a proper plateful on the day and enough left for a decent sandwich the next. If leftovers matter to you – and for a lot of households they matter more than the lunch itself – go up to 600g per person and you will be carving cold turkey happily until the 28th.

For a crown, which is the two breasts on the bone with the legs removed, allow 300g to 350g per person. There is less waste, so the number comes down. For a boned and rolled breast, where every gram is meat, 200g to 250g per person is plenty.

Two things nudge those numbers. First, how many children are at the table – two under-eights count as one adult in our experience. Second, how much else you are putting out. If there are pigs in blankets, three sorts of potato, a mountain of sprouts and a ham on the sideboard, nobody is going hungry on 400g of turkey.

Servings by weight

Whole bird

A free-range whole turkey is the classic – legs, wings, the lot, and the carcass afterwards for stock.

• 3.5kg to 4kg – serves 6 to 8
• 4.5kg to 5kg – serves 8 to 10
• 5.5kg to 6kg – serves 10 to 12
• 6.5kg to 7kg – serves 12 to 14
• 7.5kg to 8kg – serves 14 to 16
• 9kg and above – serves 18 to 20

Crown

A free-range turkey crown is the answer for anyone who wants white meat, an easier carve and a shorter time in the oven.

• 2kg – serves 4 to 5
• 2.5kg to 3kg – serves 6 to 8
• 3.5kg to 4kg – serves 8 to 10
• 4.5kg to 5kg – serves 10 to 12

Breast roll

A free-range turkey breast roll is boned and tied, so it carves into neat slices with no bone to negotiate. Good for smaller tables and very good indeed if you are cooking two meats.

• 1kg – serves 4 to 5
• 1.5kg – serves 6 to 8
• 2kg – serves 8 to 10

Crown or whole bird?

This is worth a moment’s thought rather than simply defaulting to what you had last year.

A whole bird gives you both sorts of meat. The legs and thighs are darker, richer and more forgiving, and they are what makes a curry or a pie on the 27th taste of something. You also get a carcass, which is the beginning of the best stock you will make all year. The trade-off is time in the oven and the fact that breast and leg want slightly different treatment.

A crown cooks faster, more evenly, and carves beautifully. It also fits in an oven that is already fighting for space. If your family only ever eats the breast, a crown stops you cooking legs that end up in the bin. And if you want the best of both, buy a crown and a couple of turkey legs alongside it – roast the legs separately, or slow-cook them the day before, and you have dark meat, stock bones and a crown that comes out of the oven an hour earlier.

One practical point before you commit to a big bird: measure your oven. A 9kg turkey in a roasting tin needs more room than people expect, and it needs to come out and go back in again for basting. If it is going to be a wrestling match, two smaller birds or a crown plus legs is the calmer choice.

Defrosting: give it longer than you think

If your bird is frozen, this is the part that catches people out, and it is the one bit of Christmas timing you genuinely cannot rush.

• In the fridge at 4C – allow 10 to 12 hours per kilo
• In a cool room at around 10C to 15C – allow 3 to 4 hours per kilo

So a 5kg bird wants two and a half days in the fridge. A 7kg bird wants three. Work backwards from the moment you want to start cooking, then add half a day of slack, because an oven cannot fix a turkey that is still icy in the middle. Stand it in a tray to catch any liquid, keep it covered, and check the cavity – if there is any ice in there, or the legs still feel stiff, it is not ready.

A fresh bird needs none of this. Take it out of the fridge an hour or two before it goes in the oven so it is not fridge-cold at the centre.

Cooking times per kilo

Oven at 180C, or 160C fan. Times are a guide, not gospel – ovens vary enormously and a probe thermometer is the best five pounds you will spend this Christmas.

• Whole bird under 4.5kg – 45 minutes per kilo, plus 20 minutes
• Whole bird over 4.5kg – 40 minutes per kilo, plus 20 minutes
• Crown – 40 minutes per kilo, plus 20 minutes
• Breast roll – 40 minutes per kilo, plus 20 minutes

Rough numbers, then: a 4kg bird is around three hours, a 6kg bird around four and a quarter, an 8kg bird around five and a half. A 3kg crown is about two hours and twenty minutes.

Cover the breast loosely with foil for the first two thirds, then take it off to colour. Baste when you remember. It is done when a probe pushed into the thickest part of the thigh, not touching bone, reads 70C and holds there for a couple of minutes, and the juices run clear. On a crown, probe the deepest part of the breast.

Resting is not optional

Rest a crown for 30 minutes and a large whole bird for 45. Cover it loosely, sit it somewhere warm, and use that window for the roast potatoes, which want a hot oven and a generous spoonful of goose fat. The turkey will be hotter than you expect after resting, it will carve far more cleanly, and the juices will stay in the meat rather than running out across the board.

A last word on ordering

Order early and tell us the numbers rather than the weight – how many adults, how many children, and whether you want leftovers. We do this arithmetic several hundred times a season and we would far rather send you home with the right bird than the one you guessed at. And if you are genuinely between two sizes, take the larger. Nobody has ever regretted cold turkey.