Turkey Cooking Time Calculator

Minutes = weight in kg × minutes per kg + extra minutes · Hours = minutes ÷ 60 · Defrost hours = weight in kg × 10 to 12

weight in kg

The weight of the bird, in kilograms

minutes per kg

45 under 4.5 kg, 40 between 4.5 and 6.5 kg, 35 over 6.5 kg

extra minutes

20 minutes, added only to birds under 4.5 kg

10 to 12

Hours of defrosting per kilogram in a fridge

180

Oven temperature in Celsius — 160°C fan, 350°F, gas mark 4

Use it on the morning you are cooking, once the bird is out of the fridge and you know what it weighs. It answers the two questions that decide the day: when the turkey has to go in for the meal to land at the right time, and whether it will be thawed at all. The numbers below double as a check on the instructions printed on the wrapper, which are usually written for a different oven and a different country.

1. A 5 kg turkey

   1. 5 kg falls in the middle band, 4.5 to 6.5 kg, which roasts at 40 minutes per kilogram
   2. 5 × 40 = 200 minutes, with no extra minutes added — the extra 20 applies only below 4.5 kg
   3. 200 minutes is 3 hours 20 minutes
   4. Defrosting: 5 × 10 = 50 hours at the fast end and 5 × 12 = 60 at the slow end, so two to two and a half days in the fridge
   5. Oven: 180°C, which is 160°C in a fan oven, 350°F, or gas mark 4

   Put it in at 11:00 to eat at 14:20, but leave the resting time on top of that — the timetable covers roasting only, and a bird this size wants 30 minutes out of the oven before it is carved.

2. A 3 kg turkey

   1. 3 kg is under 4.5 kg, so it roasts at 45 minutes per kilogram
   2. 3 × 45 = 135 minutes
   3. The smallest band carries an extra 20 minutes: 135 + 20 = 155
   4. 155 minutes is 2 hours 35 minutes
   5. Defrosting: 3 × 10 = 30 hours to 3 × 12 = 36 hours in the fridge

   The added 20 minutes is the part of the timetable people skip, and on a small bird it is a seventh of the total. The reason the small band roasts slower rather than faster is that a small turkey has a higher proportion of bone and cavity to meat, so the meat is closer to the oven air — it needs the gentler rate, not a shorter one.

This is the UK Food Standards Agency's timetable, and it is British in two ways that matter. Its weight bands split at 4.5 and 6.5 kilograms, and its oven is 180°C on a conventional setting; a US recipe will usually give 325°F (163°C) and a time in minutes per pound, and the two do not produce the same answer. The FSA also states plainly that its guidelines assume a bird that is not stuffed, and recommends cooking the stuffing in a separate dish — so there is no stuffed-turkey option here, because no reachable source publishes a timetable for one. A core temperature is not a pass or fail reading either: the five pairs in the table are five points on the same curve of equivalent lethality, so 60°C held for 45 minutes and 80°C held for 6 seconds are the same standard, not four levels of doneness. In practice that means a thermometer read at the moment you pull the bird out proves very little unless you hold it there; the reliable check is that the meat is steaming hot all the way through and the juices run clear. Finally, the defrost times assume a fridge at 4°C or below, and a bird thawed on a worktop or in water is a different calculation entirely — and not a safe one.

How long do I cook a turkey for?

At 180°C: 45 minutes per kilogram plus 20 minutes for a bird under 4.5 kg, 40 minutes per kilogram between 4.5 and 6.5 kg, and 35 minutes per kilogram above 6.5 kg. In practice that is 2 hours 35 for a 3 kg bird, 3 hours 20 for a 5 kg bird and 5 hours 15 for a 9 kg one. The timetable assumes the turkey is not stuffed.

Should I cook the stuffing inside the turkey?

The UK Food Standards Agency's advice is no — cook it separately. Its cooking times are explicitly based on a bird that is not stuffed, which is why this page has no stuffed option: putting stuffing in the cavity slows the heat reaching the centre, and a stuffed bird needs longer than these times give. A separate dish also means the stuffing reaches a safe temperature rather than sitting inside raw meat.

How long does a turkey take to defrost?

Ten to twelve hours per kilogram in the fridge, so 50 to 60 hours for a 5 kg bird and 90 to 108 hours for a 9 kg one — two to four and a half days. A 5 kg turkey put in the fridge on Monday morning is ready on Wednesday. Defrosting at room temperature is not a faster version of the same thing: the outside of the bird spends hours in the range where bacteria multiply.

What temperature should a turkey reach inside?

There are five equivalent answers rather than one: 60°C held for 45 minutes, 65°C for 10 minutes, 70°C for 2 minutes, 75°C for 30 seconds, or 80°C for 6 seconds. All five achieve the same reduction in bacteria, so which one you aim for depends on how precisely you can hold a temperature. Since a domestic oven cannot hold 60°C for 45 minutes in the middle of a bird, the practical target is the hot end — probe the thickest part of the thigh and check the juices run clear.

Why does a small turkey take longer per kilogram?

Because of the ratio of meat to bone and cavity. A 3 kg bird has proportionally more bone and less meat than a 9 kg one, so its meat sits closer to the oven air and to the hot cavity, and it dries out sooner if you push the temperature. That is why the smallest band roasts at 45 minutes per kilogram plus 20 minutes, while a bird over 6.5 kg roasts at 35 minutes per kilogram with nothing added.

• Christmas food hygiene — defrosting, cooking times and temperatures — UK Food Standards Agency
• Approximate Conversions from U.S. Customary Measures to Metric — National Institute of Standards and Technology