A T-bone and a porterhouse are the same steak at heart. Both come from the short loin, both carry the T-shaped bone, and both give you strip steak on one side of the bone and tenderloin on the other. The difference is where the steak is cut along the loin, and that decides how much tenderloin you get. A porterhouse is cut from the rear of the short loin where the tenderloin runs thick, so it carries a wide section of tenderloin. A T-bone is cut further forward where the tenderloin tapers thin, so its tenderloin section is much smaller.
Key Takeaways
- A porterhouse must have a tenderloin section at least 1.25 inches wide under USDA rules. A T-bone needs only 0.5 inches.
- Porterhouse steaks usually weigh 24 to 40 ounces and feed two people. T-bones usually weigh 16 to 24 ounces and feed one hungry person.
- Both steaks cook the same way. Protect the tenderloin side from the highest heat because it cooks faster and dries out sooner than the strip side.
- Buy the porterhouse when you want the full two-steak experience. Buy the T-bone when you want the same flavour for less money.
What Is a T-Bone Steak?
A T-bone is cut from the front to middle section of the short loin. The T-shaped lumbar bone runs down the centre of the steak. On the larger side sits the strip steak, the same muscle you get in a New York strip, firm and beefy with a tight grain. On the smaller side sits a piece of tenderloin, the muscle used for filet mignon. Because the tenderloin tapers as it runs forward through the loin, the tenderloin piece on a T-bone is small, often just a bite or two.
I cook T-bones when I want strip steak flavour with a small taste of tenderloin on the side. In my kitchen tests a 20 ounce T-bone gives you roughly 14 ounces of strip and only 2 to 3 ounces of tenderloin once the bone comes out. It is a strip steak first and a two-muscle steak second.
What Is a Porterhouse Steak?
A porterhouse is cut from the rear end of the short loin, where the tenderloin is at its widest. The layout is identical to a T-bone, strip on one side and tenderloin on the other, but the tenderloin section is big enough to count as a proper portion of filet mignon in its own right. A good porterhouse gives you two complete steaks joined by one bone, which is why steakhouses sell it as a sharing cut for two.
When I tested both cuts side by side at the same thickness, the porterhouse tenderloin ate like a small filet, soft right through, while the T-bone tenderloin was gone in two bites. That tenderloin portion is the entire reason the porterhouse exists, and it is what you pay extra for.
The USDA Rule That Separates Them
The names are not marketing. The USDA Institutional Meat Purchase Specifications draw a measured line between the two cuts based on the width of the tenderloin at its widest point, measured parallel to the bone. A porterhouse must measure at least 1.25 inches of tenderloin width. A T-bone must measure at least 0.5 inches. Anything under 0.5 inches cannot be sold as either name, and butchers usually sell it as a bone-in strip steak instead. You can read the specification on the USDA Agricultural Marketing Service site.
This rule matters when you shop. Some shops label any thick T-bone a porterhouse and charge porterhouse money for it. Check the tenderloin side before you pay. If the tenderloin looks like a narrow sliver, you are looking at a T-bone whatever the label says.
T-Bone vs Porterhouse: Side by Side
| Detail | T-Bone | Porterhouse |
|---|---|---|
| Cut position | Front to middle of the short loin | Rear of the short loin |
| Tenderloin width (USDA minimum) | 0.5 inches | 1.25 inches |
| Typical weight | 16 to 24 ounces | 24 to 40 ounces |
| Muscles | Strip plus a small piece of tenderloin | Strip plus a full portion of tenderloin |
| Typical price | Lower per pound | Higher per pound |
| Best for | One person who wants strip flavour | Two people sharing one steak |
Flavour and Texture Differences
The strip side tastes the same on both steaks because it is the same muscle. Expect a firm bite, strong beef flavour, and good fat from the marbling and the fat cap along the edge. The tenderloin side is the softest muscle on the animal, with a fine grain and a mild, buttery flavour. The porterhouse gives you more of that contrast in every serving. On a T-bone the contrast is a garnish. On a porterhouse it is half the meal.
One honest point in the T-bone’s favour: because the whole steak is smaller, it cooks a little more evenly, and the strip side usually carries slightly better marbling than the strip on a large porterhouse. If you mostly eat the strip and treat the tenderloin as a bonus, the T-bone is the smarter buy.
How to Cook a T-Bone or Porterhouse
Cook both steaks exactly the same way. The method below works for any steak 1.5 inches thick or more, and our full steak doneness guide covers the temperature targets in detail.
For a leaner cut, see our top sirloin steak guide.
- Salt the steak on all sides with kosher salt, about 1 teaspoon per pound, and rest it uncovered on a rack in the fridge for at least 4 hours and up to 24 hours. This dry brine seasons the meat through and dries the surface for a better crust.
- Take the steak out 45 minutes before cooking. Pat it completely dry.
- Sear it in a ripping hot cast iron pan or over direct grill heat for 3 to 4 minutes per side until a deep brown crust forms.
- Move the steak to gentle heat, a 225 degree F oven or the cool side of the grill, and cook until the strip side reads 120 to 125 degrees F for medium rare.
- Position the steak so the tenderloin side sits furthest from the heat source during the gentle phase. The tenderloin cooks faster than the strip and turns dry and grey if it takes the full heat.
- Rest the steak on a warm board for 10 minutes. The temperature will climb about 5 degrees as it rests.
- Cut both muscles off the bone, slice them against the grain, and serve the slices fanned around the bone.
For reference, the USDA recommends cooking fresh beef steaks to 145 degrees F with a 3 minute rest, which lands closer to medium. The FoodSafety.gov temperature chart lists the full guidance. Most steak cooks pull earlier for medium rare and accept the small trade-off for tenderness.
Which One Should You Buy?
Buy the porterhouse when two people will share it, when you love filet mignon as much as strip, or when the steak is the whole event. Buy the T-bone when you cook for one, when strip is your favourite cut anyway, or when the price gap is wide. At my butcher the porterhouse usually costs 20 to 30 percent more per pound, and that premium buys tenderloin and nothing else. If tenderloin is not the point of your meal, the T-bone gives you the same bone, the same strip, and the same grill theatre for less.
Frequently Asked Questions
What is the main difference between a T-bone and a porterhouse?
The size of the tenderloin section. A porterhouse is cut from the rear of the short loin and must carry at least 1.25 inches of tenderloin width under USDA rules. A T-bone is cut further forward and needs only 0.5 inches.
Is a porterhouse better than a T-bone?
It is bigger and gives you a full portion of tenderloin, but the strip side tastes the same on both steaks. The porterhouse is better value for two people sharing. The T-bone is better value for one person.
Why is porterhouse more expensive?
Only the last few cuts at the rear of each short loin qualify as porterhouse, and tenderloin is the most expensive muscle on the animal. Scarcity plus tenderloin content sets the price.
How thick should a T-bone or porterhouse be?
Aim for 1.5 to 2 inches. Thinner steaks overcook before the crust forms, and both cuts are sold thick because the bone needs room on the cutting board and in the pan.
Can one porterhouse feed two people?
Yes. A 32 to 40 ounce porterhouse gives each person a full serving of strip plus several slices of tenderloin. It is the classic steakhouse sharing cut.
Do you cook a T-bone differently from a porterhouse?
No. Use the same sear and gentle finish for both, and keep the tenderloin side away from the strongest heat so it stays medium rare while the strip finishes.
Is a porterhouse a T-bone?
Yes, both are T-bone family cuts from the short loin. The porterhouse is the rear cut with the full tenderloin, and it must have a tenderloin at least 1.25 inches wide, while a T-bone needs only 0.5 inches.
What two cuts are in a T-bone steak?
Strip steak on the larger side.
Tenderloin on the smaller side.