Cooking tri-tip for 10-15 minutes per pound gives you a roast that is well-done on the ends, and gradually gets rarer towards the center. When using an oven probe, or a meat thermometer, cook the tri-tip until the internal temperature in the thickest part reads: 125°F for rare 135°F for medium-rare 145° for medium 150° for medium-well 160° for well-done Tip: If you need a visual reference to what rare through well-done really means, check out this informative link: certifiedangusbeef.com