Activities Sports & Athletics NASCAR Race And Track Lengths How does NASCAR figure out how many laps to run? Share PINTEREST Email Print Jeff/Flickr/CC BY-SA 2.0 Sports & Athletics Car Racing Baseball Bicycling Billiards Bodybuilding Bowling Boxing Cheerleading Extreme Sports Football Golf Gymnastics Ice Hockey Martial Arts Professional Wrestling Skateboarding Skating Paintball Soccer Swimming & Diving Table Tennis Tennis Track & Field Volleyball Other Activities Learn More By Steve McCormick Steve McCormick Steve McCormick has written about NASCAR racing and has appeared as a car racing expert on ESPN Radio, Sirius Satellite Radio, and Fox Sports Radio. Learn about our Editorial Process Updated on 03/26/18 Which is longer, the Sharpie 500 at Bristol or the Aarons 499 at Talladega? How does NASCAR know how many laps to race each weekend? Is it laps, miles or something else? These are popular questions that even seasoned NASCAR fans have. How To Measure A Race Track First, we need to know how to measure a race track. Obviously, if you run up around the outside wall you are traveling significantly farther than if you are down at the bottom of the turn. So how does NASCAR measure? They measure track length from the point 15-feet in from the outside wall. This means that at many tracks the drivers are traveling a shorter distance than advertised (but not by much). The Problem With Race Naming Now that we know how to measure a track, what does that tell us about the Sharpie 500 vs. the Aarons 499? Nothing yet. Let's look at race distance. The number at the end of the race name could be talking about laps, miles, or even kilometers. NASCAR works with the tracks to find an appropriate race length that fits nicely into a TV window. So just by hearing that the race is called the Checker Auto Parts 500, you don't really know how far the cars are going to drive without more research. One Vote For Miles, Rounded Up Talladega Superspeedway measures a massive 2.66 miles. High speeds there mean that 499 miles can be covered nicely in a TV window. At Talladega if the race were 187 laps long they would only have covered 497.42 miles while 188 laps are 500.08 miles so which do they use? NASCAR always rounds up so the Aarons 499 is 188 laps long and actually goes 500.08 miles. It's a nice marketing trick that 499 miles are exactly the same race distance as 500 miles at Talladega. One Vote For Laps Bristol Motor Speedway measures 0.533 miles around. Because of the slower speeds of the short track it works out that 500 laps make the best race distance. So the Sharpie 500 in Bristol is actually 266.5 miles long. As a rule of thumb, short track races are measured in laps, most everything else is measured in miles. There are some exceptions but you'd mostly be right with this rule. An Exception To The Rule One of those exceptions is Phoenix International Raceway. Every fall they run the Checker Auto Parts 500 on the 1-mile oval. Easy right? Since 500 laps equal 500 miles then that must be the answer. Nope, sorry. It turns out that it takes too long to run 500 miles on the relatively flat track so NASCAR got creative there and declared the official race distance to be 500 kilometers. So the Checker Auto Parts 500 in Phoenix is actually 312 laps and 312 miles long. Road Courses Shoot For 350 Kilometers Road racing is a whole different ballgame. NASCAR tries to run the Cup cars approximately 350 kilometers (220 miles) for road races. The Dodge/Save Mart 350 at Infineon Raceway on the 1.99-mile road course comes out to 110 laps and they actually travel 352.3 kilometers. Finally, the Sirius at The Glen on Watkins Glen International's beautiful road course. They don't even pretend to tell you how long the race is. They typically run 90 laps on the 2.45 mile "short course" at The Glen which makes the total race distance 220.5 miles or 355.005 kilometers. Summing Up The Rules Confused yet? Just remember, short tracks are laps, speedways are miles, road races are kilometers and you'll be ready to roll.