For a typical pork tenderloin, you’ll roast it in the oven for about 20–30 minutes, but the real key is cooking to an internal temperature of 145°F and then letting it rest for 5–10 minutes.

Quick Scoop

  • At 375°F: about 20–25 minutes for a standard tenderloin, then rest 10 minutes.
  • At 400–425°F: usually 20–30 minutes total, depending on size and whether you sear it first.
  • Doneness rule: pull it when the thickest part hits 145°F on an instant‑read thermometer for juicy, slightly pink meat.
  • Weight matters: around 25 minutes for a 1 lb tenderloin at 400°F; check a bit earlier if it’s under 1 lb.

Simple method (example)

  1. Preheat oven to 400°F.
  2. Pat the pork tenderloin dry, rub with oil and seasoning.
  3. Optional but tasty: quickly sear it in a hot pan on all sides, 2–3 minutes per side, then transfer to the oven.
  1. Roast until internal temp reaches 145°F (start checking around 20 minutes).
  1. Let rest 5–10 minutes before slicing so the juices redistribute.

Why times vary

  • Oven temp (375 vs 400 vs 425°F) changes how fast the outside browns and the inside cooks.
  • Tenderloin size (under 1 lb vs over 1 lb) shifts cook time by 5–10 minutes or more.
  • Starting temp (fridge‑cold vs closer to room temp) affects how quickly it reaches 145°F.

If you’re ever unsure, trust the thermometer over any fixed time: once you see 145°F in the center, you’re safe to pull it and rest it for a juicy result.