Turkey Size Calculator (pounds of turkey per person, thawing & roasting time)

Understanding the turkey size calculator — concept and principle

This calculator works out how big a whole turkey to buy for a holiday meal from the number of adults and children and how many leftovers you want. It also gives the thawing time in the fridge or in cold water and the roasting time at 325 °F, following US food-safety guidance.

Children count as half an adult here; leftovers add a quarter more.

How it is calculated

Pounds = (adults + children × child portion) × (1 + leftovers)

Number of turkeys = pounds ÷ 24, rounded up (at least 1)

Weight of each turkey = pounds ÷ number of turkeys

Fridge thawing (days) = weight ÷ 4; cold-water thawing (hours) = weight × 0.5

Roasting time is read from the USDA FSIS timetable for an unstuffed whole turkey at 325 °F (163 °C).
kg = lb × 0.45359237.

The principle

The USDA Food Safety and Inspection Service suggests 1 lb of whole turkey per person. A whole bird is largely bone, so one pound of raw turkey gives a good serving of meat. Children eat less, so they count as a share of an adult. The FSIS roasting table stops at 24 lb, and very large birds are hard to cook evenly, so a bigger total is split into two or more turkeys. Thawing in the fridge takes about 24 hours per 4–5 lb; the calculator uses the slower 4 lb a day. In cold water changed every 30 minutes it takes about 30 minutes per lb.

Worked example

Default inputs: 8 adults, 2 children at 50 %, 25 % extra for leftovers.

People = 8 + 2 × 0.5 = 9 adult portions.
Pounds = 9 × 1.25 = 11.25, shown as 11.3 lb or 5.1 kg.
11.25 ÷ 24 is below 1, so 1 turkey of 11.3 lb.
Fridge thawing = 11.25 ÷ 4 = 2.8 days; cold water = 11.25 × 0.5 = 5.6 hours.
The FSIS table for an unstuffed 8–12 lb turkey: 2 h 45 min – 3 h 00 min at 325 °F.

Each point is the calculator re-run with only “Adults” changed; the gold point is the default example. Change the inputs above and this chart follows your numbers.

Adults	Turkey to buy (lb)
2	3.8
4	6.3
6	8.8
8	11.3
10	13.8
12	16.3
16	21.3

How to read the result

Turkeys are sold in whole sizes, so buy the nearest bird at or slightly above the weight shown. Round the fridge days up and start early: 2.8 days means starting at least three days before roasting. Begin checking the temperature at the short end of the roasting range. Let the bird rest about 20 minutes before carving.

Common mistakes

Counting a boneless turkey breast as a whole bird; boneless meat needs less weight per person.
Starting to thaw too late and roasting a partly frozen bird.
Thawing at room temperature.
Trusting the pop-up timer instead of a thermometer.

Keep in mind: This is a planning aid based on USDA guidance. Always check that the thigh, wing and thickest part of the breast reach 165 °F (74 °C) with a food thermometer.

Frequently asked questions

How much turkey per person?

About 1 lb of whole turkey per person, plus extra if you want leftovers.

How long to roast a 12 lb turkey?

About 2¾ to 3 hours unstuffed at 325 °F, by the FSIS timetable.

Can I roast a turkey from frozen?

FSIS says it is safe, but it takes at least about 50 % longer than a thawed bird.

Sources: USDA Food Safety and Inspection Service, "Let's Talk Turkey — A Consumer Guide to Safely Roasting a Turkey"

Checked 9 Nov 2026. USDA Food Safety and Inspection Service, “Let’s Talk Turkey — A Consumer Guide to Safely Roasting a Turkey” (2004, revised 2010): 1 lb per person; refrigerator thawing about 24 hours per 4–5 lb; cold-water thawing about 30 minutes per lb; roasting timetable at 325 °F; 165 °F in the thigh, wing and thickest part of the breast; 20 minutes’ rest. 1 lb = 0.45359237 kg (exact). Child portion and leftover share are example values.

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