Plan for about 35 minutes per pound at 225°F — roughly 4 hours for a typical 6 lb cut. But the clock is only a guide: pull it at 130°F internal, when it's probe-tender. Build in 1–2 hours of buffer for the stall and a proper rest.
Pro tip
Smoke to 125–130°F for medium-rare, then sear. It climbs ~5°F while resting.
Cook to temp, not time
Every smoke is different — wind, humidity, how often you open the lid, and the cut itself all change timing. A good wireless thermometer is the single best upgrade for consistent BBQ: set the target, and cook until it hits, not until the timer says so.
FAQ
How long does it take to smoke prime rib?
About 35 minutes per pound at 225°F — roughly 4 hours for 6 lbs, but always finish by internal temperature (~130°F) rather than the clock.
What temp do you pull prime rib?
Pull prime rib at about 130°F internal, then rest before serving.