Roasting time is the weight multiplied by a minutes-per-pound rate for the cut. An unstuffed turkey at 325°F takes about 15 minutes per pound, so a 12 lb bird needs roughly 180 minutes, or 3 hours. Treat the figure as a start time for thermometer checks; the meat is done when it reaches its safe internal temperature.
Planning a holiday dinner or a Sunday roast starts with one question: when does the meat go in? This calculator takes the weight of a whole turkey, whole chicken, beef roast, pork loin, leg of lamb or fully cooked ham, in pounds or kilograms, and returns the roasting time in minutes and in hours and minutes. It also shows the oven temperature the rate assumes and the internal temperature the thickest part must reach. The rates come from the per-pound figures in USDA roasting timetables. They assume a thawed piece, a conventional oven and an unstuffed bird; a convection fan, a stuffed cavity, bone-in versus boneless shape and how often the door opens all shift the real time, so a probe thermometer has the final word.
Choose turkey, chicken, beef, pork loin, lamb or reheated ham from the list; each has its own rate and oven setting.
Type the weight from the packaging label and set lb or kg in the box beside the number.
The minutes, the hours-and-minutes figure, the oven temperature and the target internal temperature update as you type.
Result Roasting time (minutes): 180
In hours and minutes: 3 h 0 min
Oven temperature: 325°F (163°C)
Safe internal temperature: 165°F (74°C)
Rate used: 15 min per lb
At 325°F a 12 lb bird lands at the start of the USDA 3 to 3¾ hour window, so start checking the thigh with a thermometer at the 3-hour mark.
Result Roasting time (minutes): 88
In hours and minutes: 1 h 28 min
Oven temperature: 325°F (163°C)
Safe internal temperature: 145°F (63°C), then rest 3 min
Rate used: 20 min per lb
2 kg is 4.41 lb; at 20 minutes per pound and 325°F that is just under an hour and a half for a medium roast.
Result Roasting time (minutes): 80
In hours and minutes: 1 h 20 min
Oven temperature: 350°F (177°C)
Safe internal temperature: 165°F (74°C)
Rate used: 20 min per lb
A 4 lb bird at 350°F needs about 1 h 20 min; the breast and thigh must both read 165°F.
t = W × r, where W in kg is first converted with W(lb) = W(kg) ÷ 0.45359237
tWrRates are 15 min/lb for turkey and 25 for lamb at 325°F, 20 for beef at 325°F, 20 for chicken and pork loin at 350°F, and 12 for reheating a fully cooked ham at 325°F. They sit inside the ranges USDA FSIS publishes. Per-pound timing is linear, while real heat transfer slows as a piece gets thicker, so very large birds finish slightly faster per pound than the rule suggests.
At 15 minutes per pound and 325°F, an unstuffed 20 lb turkey needs about 300 minutes, or 5 hours. USDA lists 4¼ to 5 hours for 20 to 24 lb, so begin checking the thigh at about 4¼ hours.
Into the thickest part of the meat, away from bone and fat. For poultry, check the innermost thigh, the wing joint and the thickest part of the breast; all three must read 165°F.
No. The time shown is oven time only. Beef, pork and lamb need a three-minute rest after reaching 145°F, and larger roasts are often rested 15 to 20 minutes before carving so juices settle.
USDA lowered whole-cut pork from 160°F to 145°F with a three-minute rest in 2011. Ground pork still needs 160°F. The rest lets the temperature hold long enough to make the meat safe.
You can, but the per-pound rates here no longer apply. Higher heat browns the outside faster and widens the gap between surface and centre, so rely on the thermometer and expect the outer layer to be more done.
Often slightly, because the shape is more compact and even, though bone conducts heat poorly so the effect varies. The calculator uses one rate per food; check the internal temperature 15 to 20 minutes before the predicted time.
Using this tool in an assignment, article or report? Copy a citation, or a link for your website.
Tools Directory Editorial Team. (2026, October 20). Cooking Time Calculator. Tools Directory. Retrieved October 26, 2026, from https://tools.milunir.com/cooking/cooking-times-and-temperatures/cooking-time-calculator/
Tools Directory Editorial Team. “Cooking Time Calculator.” Tools Directory, 20 Oct. 2026, https://tools.milunir.com/cooking/cooking-times-and-temperatures/cooking-time-calculator/. Accessed 26 Oct. 2026.
Tools Directory Editorial Team. “Cooking Time Calculator.” Tools Directory. Last modified October 20, 2026. Accessed October 26, 2026. https://tools.milunir.com/cooking/cooking-times-and-temperatures/cooking-time-calculator/.
<a href="https://tools.milunir.com/cooking/cooking-times-and-temperatures/cooking-time-calculator/">Cooking Time Calculator – Tools Directory</a>