Cooking · roasting

Prime rib cooking time calculator

Bone-in prime rib by weight — with the pull temperature for medium-rare and the carryover that finishes it during the rest.

In short

A 6 lb bone-in rib roast at 325°F takes roughly 2¼–2½ hours. For medium-rare (135°F final), pull it around 126°F — carryover adds 8–10°F during a 15–30 minute rest. Note 135°F is below the USDA 145°F minimum, a common preference for healthy adults.

Roast details

Roasting plan
Pull from oven at136°F
Final after rest145°F
Carryover rise+8–10°F
Time
Rest

About this estimate

This page locks the prime rib cooking time into the roasting calculator. Time is a planning estimate — oven calibration, shape, bone, and starting temperature all change it. The reliable test is a probe thermometer in the thickest part, away from bone: pull at temperature, not at the clock.

Need a different cut or weight? Use the full roasting time calculator.

What temperature do I pull prime rib for medium-rare?
Around 126°F, so it climbs to about 135°F after carryover. For medium, pull near 136°F for a 145°F final — which also meets the USDA safe minimum.
How long does prime rib take per pound?
Roughly 23–25 minutes per pound bone-in at 325°F, but cook to temperature, not time — a probe thermometer is the only reliable guide.
Is medium-rare prime rib safe?
Medium-rare (135°F) is below the USDA 145°F minimum. It's a common choice for healthy adults, but the safe minimum is 145°F with a 3-minute rest.

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