Related Arby's Questions. How many weight watchers points are in a large beef and cheddar from Arby's? In an Arby's Beef 'N' Cheddar Sandwich there are 12 Weight Watchers points. That's... How many calories does a Roast Beef and Cheddar from Arby's have? In an Arby's Beef and Cheddar there are 445 calories and 21grams of fat. How many calories are in an Arby's roast beef and cheddar and a medium fry? An Arby's Melt has 303 calories while a medium fry contains 505 calories. They... how many calories in a Arbys beef and cheddar The Arbys Beef n' Cheddar is 510 calories.