How long to cook roast beef
Choose a method and size for a practical estimate; cooking times are ranges, not a substitute for checking doneness. How we calculate times.
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Adjust exact weight, thickness or quantity when you need to.
Estimated cooking time
1 hr 2 min – 1 hr 13 min
- Oven temp
- 400°F / 200°C
- Rest
- 15 min
- Doneness target
- 129°F / 54°C
- Food safety guidance
- Official minimum: 145°F / 63°C + 3-min rest USDA Food Safety and Inspection Service
Culinary preference — not a safety minimum.
Evidence-informed estimate · Cooking times vary — follow the food-specific completion and food-safety guidance.
- Bring to room temperature and salt a day ahead for best results. Sear in a hot pan before and after roasting.
- Times assume the food starts refrigerated, not room temperature.
- USDA recommends 63°C (145°F) with a 3-minute rest for whole beef cuts. A lower culinary doneness is a personal preference and is not the official minimum.
Roast beef cooking time by size
| Size | Approximate | Time |
|---|---|---|
| Small (1 kg) | ≈1 kg, serves 4 | 1 hr 2 min – 1 hr 13 min |
| Medium (1.5 kg) | ≈1.5 kg, serves 6 | 1 hr 2 min – 1 hr 13 min |
| Large (2.5 kg) | ≈2.5 kg, serves 10 | 1 hr 2 min – 1 hr 13 min |
How to know when it's done
Time is an estimate — temperature is the truth. Check the thickest part with an instant-read thermometer: roast beef is safely done at 145°F / 63°C. USDA recommends 63°C (145°F) with a 3-minute rest for whole beef cuts. A lower culinary doneness is a personal preference and is not the official minimum.
Food-level cooking reference: BBC Good Food — How to cook roast beef (checked 2026-08-18). CookCue applies deterministic adjustments; food-safety guidance is sourced separately.
Frequently asked questions
How long does 1 kg of beef take for medium rare?
About 50 minutes at 200°C, plus 15 minutes resting. Pull the roast at 52°C internal — it climbs to 54°C while resting.
Do I need to sear a beef roast?
Searing before (or after) roasting adds flavour and colour. It does not seal in juices, but a 2-minute sear per side is worth it.