How Long to Cook a Turkey

Minutes per pound is not a constant

Work the USDA's own roasting brackets back into a per-pound rate and it doesn't hold still:

Bird	USDA minimum	Implied rate
8 lb	2h 45m	20.6 min/lb
16 lb	3h 45m	14.1 min/lb
24 lb	4h 30m	11.3 min/lb

Cooking time is governed by how long heat takes to reach the centre, and that doesn't scale linearly with weight. Doubling the weight doesn't double the time.

So the famous flat rule lands like this:

Bird	15 min/lb says	USDA says	Verdict
8 lb	2h 00m	2h 45m – 3h	45 min EARLY
16 lb	4h 00m	3h 45m – 4h 15m	inside the bracket
24 lb	6h 00m	4h 30m – 5h	1h 30m late

The rule usually gets blamed for drying out large birds. It does. But finishing early on a small bird is the end that matters, and it's the end nobody expects.

The USDA chart, at 325°F

This calculator uses the brackets rather than a rate, because that's how they're published:

Weight	Unstuffed	Stuffed
8–12 lb	2¾–3 hrs	3–3½
12–14 lb	3–3¾	3½–4
14–18 lb	3¾–4¼	4–4¼
18–20 lb	4¼–4½	4¼–4¾
20–24 lb	4½–5	4¾–5¼

They're published as ranges because ovens differ, birds differ in shape as well as weight, and how cold it was going in changes everything. A single number would imply a precision that doesn't exist.

Use the bottom of the range as when to start checking. Not the top as when to take it out.

165°F is the answer. The clock is not

The USDA's own wording on that timetable: the times are approximate and should always be used in conjunction with a properly placed food thermometer.

165°F throughout, measured in three places:

• The thickest part of the breast
• The thickest part of the thigh
• The wing joint

That's the whole determination. Pop-up timers aren't reliable enough to be your only check. The clock tells you when to start looking; the thermometer tells you when to stop cooking.

The USDA says don't stuff it

Their position is explicit: for optimum safety, do not stuff whole poultry. It is recommended to cook stuffing outside the bird.

The reason is mechanical. The centre of the stuffing must itself reach 165°F, and it sits in the coldest part of the bird — so it routinely lags well behind the meat.

That leaves you choosing between unsafe stuffing and overcooked turkey. Which is why stuffed times run longer across the whole chart, and why, if you do stuff it, the stuffing needs its own thermometer reading.

Every time on this page assumes a fully thawed bird

The chart is built on a bird that's completely thawed and starting at refrigerator temperature, in an oven set no lower than 325°F, breast-side up on a flat rack in a shallow pan.

A partly frozen bird cooks unevenly, takes substantially longer, and gives you a thermometer reading you can't trust.

Fridge thawing takes roughly 24 hours per 4–5 lb. A 20 lb bird needs five days. That's why the calculator shows it — the single most common Thanksgiving failure isn't a timing error on the day, it's a bird that came out of the freezer on Tuesday.

How big a bird, anyway

The calculator's feeds about output works on roughly 1.25 lb of whole bird per person — bone, cavity and all, not 1.25 lb of meat.

That sounds generous and mostly isn't. A whole turkey is a substantial fraction of skeleton, and the usable yield is well under half the purchase weight. The rule also quietly assumes you want leftovers, which for most people cooking a turkey is the point.

Scale it down if you're buying a crown or a breast joint instead — those are almost all meat, and the same per-person figure would have you buying roughly twice what you need.

Rest it for 20 minutes

Before removing stuffing and before carving.

Carving is substantially easier, the juices settle, and on a stuffed bird it matters for safety too.

Plan the 20 minutes into your timings rather than discovering them while everything else goes cold. It's one of the easiest parts of the day to get wrong and one of the cheapest to get right.

Afterwards

Leftovers back in the refrigerator within 2 hours. Used within 3–4 days, or frozen.

Print the timing sheet — it has the full USDA chart, the three thermometer locations, and a countdown table to work backwards from the time you actually want to eat.

Sources: USDA FSIS, Timetable for Turkey Roasting (325 °F) · Let's Talk Turkey

Food safety guidance is the USDA's; the arithmetic is ours. When they disagree, they're right.