How long do I need to keep my rib roast in the oven

Look online. Food network has information regarding this.

Well, it depends. Here are a couple examples but it also depends if its still on the bone or not. Low temperature for a long time. At 325° F (165° C), the meat will take about 17 to 20 minutes per pound. High temperature for a shorter time. At 450° F (235° C) for the first 30 minutes and then reduce the temperature to 325° F (165° C), allow about 13 to 15 minutes per pound. Both high and low temperatures. start high to sear the outside, then turn down the oven after 30 to 45 minutes to finish.