A pork tenderloin of 1 to 1.5 lb takes 20 to 27 minutes at 400°F to reach an internal temperature of 145°F. Sear it first in an oven-safe pan and the oven portion drops to roughly 12 to 18 minutes.
That is the answer, and it is also a seven-minute window on a cut that goes from juicy to chalky in about four. Which is the argument this whole site is built on: the clock tells you when to start checking, not when it is done.
Tenderloin, by weight
| Weight | 400°F, from raw | Seared first, then 400°F |
|---|---|---|
| 0.75 lb | 16–20 min | 10–13 min |
| 1.0 lb | 20–24 min | 12–15 min |
| 1.25 lb | 22–26 min | 14–17 min |
| 1.5 lb | 24–27 min | 15–18 min |
| 2 × 1 lb, same pan | 25–30 min | 16–20 min |
Two tenderloins in one pan do not take twice as long. They take a few minutes longer, because you have added mass to the oven, not thickness to the meat. Thickness is what governs cooking time; weight is only a proxy for it.
That is why a tenderloin and a pork loin roast of the same weight are not remotely the same job.
Why tenderloin is fast and loin is not
A tenderloin is roughly 2 to 2.5 inches across. A pork loin roast of the same 1.5 lb is shorter and 4 inches across. Heat travels inward from all sides, so the time to bring the centre up scales with the square of the thickness, not with the weight on the label.
Double the diameter and the centre takes roughly four times as long to arrive.
| Cut | Approx. thickness | 400°F to 145°F |
|---|---|---|
| Pork tenderloin | 2–2.5 in | 20–27 min |
| Pork loin roast, 3 lb | 4 in | 55–75 min |
| Chicken breast, boneless | 1–1.5 in | 18–22 min (to 165°F) |
| Beef tenderloin roast, 3 lb | 3.5 in | 35–45 min (to 130°F) |
| Whole chicken, 4 lb | — | 65–80 min (to 165°F) |
Minutes-per-pound rules exist because they are easy to print, not because they are accurate. They work tolerably for one shape and mislead for every other.
The three variables no chart can hold
Starting temperature. A tenderloin straight from the fridge at 38°F has 107°F to climb. One left on the counter 40 minutes starts around 50°F and finishes 3 to 5 minutes sooner. Most recipes silently assume one or the other and never say which.
Your oven's real temperature. Domestic ovens commonly run 15 to 25°F off their dial, and they cycle — the element switches on and off around a setpoint rather than holding it. A cheap oven thermometer settles this in one evening and changes every timing you will ever use.
Carryover. Meat keeps cooking after it leaves the oven. A tenderloin gains 3 to 5°F resting; a 3 lb loin roast gains 5 to 10°F. Pull a tenderloin at 145°F and it serves at 149°F, past where you wanted it. Pull at 140°F and it lands on target.
That last point is the one that ruins the most dinners, and it is covered in full in the doneness table.
What 145°F actually means
The USDA safe minimum for whole cuts of pork, beef, lamb and veal is 145°F followed by a 3-minute rest. It was lowered from 160°F in 2011, and a great many recipes still have not caught up — which is why so much home-roasted pork is grey.
At 145°F pork tenderloin is faintly pink at the centre and safe. That is the intended result, not undercooking.
Ground pork is a different rule: 160°F, no pink, because grinding distributes surface bacteria throughout.
The practical routine
- Oven to 400°F, and give it a full 15 minutes past the beep — most ovens announce the setpoint before the walls reach it.
- Pat dry, salt, sear 2 minutes a side if you have an oven-safe pan.
- Probe into the thickest part along the length, not down through the end.
- Start checking at the low end of the range. For a 1 lb tenderloin that is 20 minutes, or 12 if seared.
- Pull at 140°F. Rest 5 to 10 minutes uncovered.
Same probe, same logic, in the air fryer — where the times are shorter and the temperature swings are wider.