Updated 30 September 2026
A porterhouse steak and a T-bone look almost identical: a T-shaped bone with sirloin on one side and fillet on the other. The difference is where along the loin the steak is cut, and that decides how much fillet you get. This guide explains exactly what a porterhouse steak is, how it compares with a T-bone, and how to cook either one. To be clear from the start: we sell T-bone steaks, not a steak labelled porterhouse, and we will explain why that makes little difference in the kitchen.
What is a porterhouse steak?
A porterhouse is a steak cut across the short loin, through the backbone, so that it includes two muscles: the sirloin (the strip loin) on one side of the bone and the fillet (tenderloin) on the other. The T-shaped bone is part of the vertebra.
The fillet is thin at the front of the loin and gets wider towards the rump. Steaks cut from the rear end, where the fillet is at its biggest, are called porterhouse. Steaks cut further forward, where the fillet is smaller, are T-bones.
In the United States, there is a rule of thumb: a porterhouse must have a fillet at least about 3cm (1¼ inches) across at its widest point; anything smaller is a T-bone. In the UK there is no such legal definition, and the names are often used loosely.
Porterhouse vs T-bone: the differences
| Porterhouse | T-bone | |
|---|---|---|
| Where it is cut | Rear of the short loin | Middle and front of the short loin |
| Muscles | Sirloin and fillet | Sirloin and fillet |
| Fillet size | Large | Smaller |
| Thickness and weight | Usually thick and heavy, a sharing steak | Varies; often a generous single steak |
| Flavour | Beefy sirloin plus a big piece of tender fillet | Beefy sirloin plus a smaller piece of fillet |
| Best cooking | Grill, barbecue, pan then oven | Grill, barbecue, pan then oven |
In short: every porterhouse is a type of T-bone, but not every T-bone is big enough to be a porterhouse. You get two steaks in one either way.
What we sell: the T-bone
Our T-Bone Steak 500-600g (£15.99) is a big, bone-in steak weighing 500–600g, with sirloin on one side of the bone and fillet on the other. We do not list a steak called porterhouse, and we will not call our T-bones porterhouse steaks, because the size of the fillet varies from steak to steak. If you want a steak for two with a generous piece of both cuts, a 500–600g T-bone is the one to choose.
How to cook a porterhouse or T-bone steak
The challenge with both steaks is that the fillet cooks faster than the sirloin. Here is how to get them both right.
- Bring it to room temperature. Take the steak out of the fridge 30–45 minutes before cooking. Pat it dry and season generously with salt.
- Heat the pan or grill. Use a heavy frying pan or griddle over a high heat, or a hot barbecue with a cooler zone. Heat the oven to 200°C (180°C fan) if you are finishing it there.
- Sear the fat edge. Hold the steak on its fat edge with tongs for 1–2 minutes to render the fat.
- Sear both sides. Cook for 3–4 minutes a side until well browned. Position the fillet side slightly away from the hottest part of the pan or grill so it cooks more gently.
- Finish. For a steak thicker than about 3cm, move it to the oven or the cooler side of the barbecue for 4–8 minutes, depending on how you like it.
- Check the temperature. As a cook's guide, 50–52°C in the sirloin for rare, 55–57°C for medium-rare and 60–62°C for medium.
- Rest for 5–10 minutes, then carve the two muscles off the bone and slice each across the grain.
The Food Standards Agency says whole cuts of beef, such as steaks, can be served pink as long as the outside is properly cooked. Our how to cook a T-bone steak guide has more detail.
How to carve and share
Cut down along the bone to release the sirloin, then the fillet. Slice each muscle across the grain into strips about 1cm thick and fan them out on a board next to the bone. That way everyone gets some of each.
Porterhouse, T-bone or two separate steaks?
If you like both cuts, a T-bone gives you them in one, with the bone adding flavour. If you prefer to control each steak separately, buy them individually: Sirloin Steak 2x 8oz (£11.99) and Fillet Steak 2x 6oz (£18.99). For a bigger bone-in showpiece, try the Tomahawk Steak 800g-1.2kg (Frozen) (£32.99), which is a ribeye on the rib bone.
Read our guide to types of steak for every cut, see live prices in steak prices UK, or browse all our steaks and T-bone steaks.
Porterhouse steak FAQs
What is the difference between a porterhouse and a T-bone?
Both are cut through the short loin and include sirloin and fillet either side of a T-shaped bone. A porterhouse is cut from the rear of the loin, where the fillet is larger; a T-bone is cut further forward, with a smaller fillet.
Is a porterhouse better than a T-bone?
Not better, just bigger on the fillet side. If you love fillet, a porterhouse gives you more of it. The sirloin side is the same.
Can you buy porterhouse steak in the UK?
Some butchers label their largest T-bones as porterhouse, but there is no formal UK definition. We sell T-bone steaks of 500–600g, which give a generous piece of both sirloin and fillet.
How do you cook a porterhouse steak?
Sear it hard on both sides and the fat edge, keeping the fillet side away from the fiercest heat, then finish in the oven or on the cool side of the barbecue. Rest it before carving.
How many people does a porterhouse or T-bone feed?
A 500–600g T-bone or porterhouse will feed one very hungry person or two with sides.