Updated 30 September 2026
Getting the cooking time for a roast beef right comes down to three things: the weight of the joint, the cut, and how pink you like it. Weigh the joint, pick your doneness from the table below, and use a probe thermometer to finish the job. The chart is worked out per kilo, so you can scale it to any joint.
Roast beef cooking times per kg: the quick answer
Take the joint out of the fridge 45 minutes to an hour before it goes in. Heat the oven to 220°C (200°C fan, gas 7). Roast for 20 minutes at that heat to colour the outside, then turn the oven down to 180°C (160°C fan, gas 4) and carry on for the time per kilo below. Rest before carving.
| Doneness | Time per kg after the first 20 minutes | Core temperature when you take it out | After resting |
|---|---|---|---|
| Rare | 30–35 minutes per kg | 48–50°C | about 52°C |
| Medium-rare | 35–40 minutes per kg | 52–54°C | about 57°C |
| Medium | 40–45 minutes per kg | 57–58°C | about 62°C |
| Well done | 50–55 minutes per kg | 65–68°C | about 70°C |
So a 1kg topside joint cooked medium is 20 minutes plus roughly 40–45 minutes: just over an hour in the oven, then 20 minutes' rest. A 2kg sirloin joint cooked medium-rare is 20 minutes plus 70–80 minutes.
Those core temperatures are a cook's guide to doneness, not a safety rule. The Food Standards Agency says whole cuts of beef, such as joints and steaks, can be served pink or rare as long as the outside has been properly cooked. Rolled joints, stuffed joints and anything minced are different: cook those until steaming hot all the way through with no pink in the middle.
Why the weight matters more than the cut
Heat travels into a joint from the outside, so a thick, compact joint takes longer per kilo than a long, thin one. That is why the per-kilo figures come as a range. Use the lower number for a long, narrow joint such as a whole fillet or a sirloin strip, and the higher number for a round, deep joint such as topside. Joints bigger than about 2.5kg need slightly less time per kilo, because the oven has more mass to work on at once, so start probing early.
Always weigh the joint yourself rather than guessing from the label, particularly if you have trimmed fat or taken off the string. A £10 probe thermometer will save you more roast dinners than any timing chart.
Cooking times by cut
Topside
Topside is lean, round and sold ready to roast, which makes it the classic Sunday joint. Because there is so little fat running through it, it goes from juicy to dry quickly once it passes medium. Roast it rare to medium, carve it thinly across the grain and serve it with plenty of gravy. Our Topside Joint 1kg is £21.99 and cooks in a little over an hour for medium. There is a full walk-through in how to cook a topside joint.
Sirloin
Sirloin has a band of fat on top that bastes the meat as it roasts, so it is more forgiving than topside and has more flavour. Score the fat lightly, season it well and sit the joint fat-side up. Use the 20-minute blast, then the times in the table. The Sirloin Joint 1kg (£27.99) suits four people; the ANGUS Sirloin Joint 4-5kg (£79.99) is a centrepiece for a crowd and needs probing from about 1 hour 45 minutes. See how to cook a sirloin joint for more.
Whole beef fillet
Fillet is the tenderest cut and the quickest to roast, because it is long and thin. Defrost it fully in the fridge, dry it, then sear it all over in a hot pan. Roast at 220°C (200°C fan) for 15–20 minutes for rare to medium-rare on a 1.2–1.5kg fillet, or 20–25 minutes on a larger one. Take it out at 50°C for rare. The Whole Beef Fillet 1.2-1.8kg (Frozen) is £59.99; our guide to how to cook a whole beef fillet covers trimming and tying.
Brisket
Brisket does not follow the per-kilo chart. It is a hard-working muscle full of connective tissue, and it needs long, gentle, wet cooking until it pulls apart. Brown it, sit it on onions with a splash of stock, cover tightly and cook at 150°C (130°C fan) for about 3–3½ hours for a 1kg joint and 4–4½ hours for 1.5kg. It is done when a fork slides in with no resistance. The Brisket Joint 1kg is £19.99, and how to cook beef brisket has the full method.
Resting and carving
Resting is part of the cooking time, not an optional extra. As the joint sits, the heat at the surface keeps moving inwards (the core usually rises another 3–5°C) and the juices settle back into the meat instead of running over the board. Rest a 1kg joint for 15–20 minutes and anything bigger for 25–30 minutes, loosely covered with foil. Use that time to make the gravy from the tin juices and to finish the potatoes and Yorkshires.
To carve, find the direction the grain runs and slice across it, as thinly as you can. Across the grain means short fibres, and short fibres mean tender slices, which matters most on a lean joint like topside.
Oven temperatures at a glance
- Searing blast: 220°C, 200°C fan, gas 7 for 20 minutes.
- Main roast: 180°C, 160°C fan, gas 4.
- Low and slow (brisket): 150°C, 130°C fan, gas 2.
Fan ovens run hotter, so if you only have a fan setting, use the fan figure. If your oven runs hot or cold, the probe is what tells you the truth.
Common mistakes
- Cooking straight from the fridge. A cold centre means a grey outer ring by the time the middle is done.
- Skipping the thermometer. Every oven is different, and so is every joint.
- Carving too soon. Ten minutes' patience is the difference between juice on the plate and juice on the board.
- Roasting brisket like topside. Brisket needs time and moisture, not a hot oven.
For help choosing the joint in the first place, read our guide to the best beef joint for roasting, or browse the whole range of beef joints, including topside and sirloin joints.
Roast beef FAQs
How long do you cook a 1kg beef joint?
For medium, roast a 1kg joint at 220°C (200°C fan) for 20 minutes, then 180°C (160°C fan) for 40–45 minutes: about 1 hour 5 minutes in total. For rare, allow 30–35 minutes after the first 20. Rest it for 15–20 minutes before carving.
How long does a 2kg beef joint take to roast?
After the 20-minute blast, allow 60–70 minutes for rare, 70–80 minutes for medium-rare and 80–90 minutes for medium. Start checking the core temperature 15 minutes before the end.
What temperature should roast beef be inside?
As a cook's guide, take it out at 48–50°C for rare, 52–54°C for medium-rare, 57–58°C for medium and 65–68°C for well done. It will rise a few degrees while it rests. The FSA says whole cuts of beef can be served pink as long as the outside is properly cooked.
Do you cover roast beef in the oven?
Not for topside, sirloin or fillet: roasting uncovered gives you a browned crust. Only cover it if the outside is colouring too fast. Brisket is different and should be covered tightly with a lid or foil for the whole slow cook.
How long should roast beef rest?
Rest a 1kg joint for 15–20 minutes and a larger joint for 25–30 minutes, loosely covered with foil. Resting lets the juices settle and finishes the cooking gently.