# How Do You Calculate Cooking Time for Prime Rib

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Last Updated on October 20, 2022

# How Do You Calculate Cooking Time For Prime Rib?

**Calculate the actual weight by 15 (minutes per pound) and then divide that number by 60 to get your approximate time**. For example: A 7.89 pound roast x 15 mins per pound = 118.35 minutes / 60 minutes per hour = 1.97 hours (2 hours). According to our formula, an 8-pound roast will take about 2 hours to cook.

### How many minutes per pound do you cook a prime rib at 350?

Either way, the main cooking is done at 350 degrees for **16 to 18 minutes a pound**, to an internal temperature of 120 degrees. For a 7-pound roast, that’s going to be about two hours.

### How long does a prime rib take to cook per pound?

In a 225 degree F oven: **Medium-rare: 30 to 35 minutes per pound**. Medium: 35 to 40 minutes per pound. Medium-well: 40 to 45 minutes per pound.

### How long does it take to cook a 10 pound prime rib at 325?

For example, with a 10 pound roast, you would expect 2 hours of total cooking time for rare (15 minutes at 500° and **1 3/4 hours** at 325°).

### What temperature and how long do you cook prime rib for?

Start by cooking your prime rib at 500°F for 15 minutes and then lower the oven temperature to 325° F and cook for 10-12 min per pound for rare prime rib, or 13-14 min per pound for medium rare prime rib, or 14-15 min per pound for medium well prime rib. A meat thermometer is essential to ensure you cook it perfectly!