Chip Times and B-Tags in Running Races

Men and woman during ultramarathon race training
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You may have heard runners talking about their "chip time" from race results. Chip time is another way of saying "net time," or the actual amount of time it takes a runner to go from the starting line of a race to the finish line.

Many races feature a timing technology in which all participants run with a computer chip attached to their running shoe. When you register for a race, you receive your borrowed chip, programmed with your information, at the same time you get your race bib. The chip usually attaches to your shoelaces, although some are connected to a Velcro strap that goes around your ankle. At the end of the race, someone will be there to collect the chip from you. Most races are now using race bibs with a timing chip or tag called a B-Tag attached to the front or back of the race bib.

As you move across a special mat at the starting line, the chip registers that you've started the race. Then, as you cross the finishing line, the chip registers that you've finished the race. So, in other words, the amount of time that it takes you to reach the starting line (since most people are not right at the front of the race) doesn't count in your overall time. In some cases of very large races, it can take runners at least 20 minutes to reach the starting line. Your chip time is different than your "gun time," which is the amount of time it took you to finish the race from the moment the gun (or horn) went off.

Most large races, especially marathons, now use chip timing technology. As a result, runners at the start can line up where it's appropriate for their pace, instead of trying to push their way to the front. For longer distances, the chip also records splits at various points along the course, such as the half-marathon mark during a marathon. This feature is helpful for your friends and family members who may want to track you online during your race.

Of course, one drawback of timing chip technology (although most runners would never admit it) is that runners can no longer "fudge" their race times by subtracting more time than it actually took for them to cross the starting line. The chip doesn't lie.


A B-Tag is a timing device that's used in many road races to determine a race participant's net time. The B-Tag registers when you cross the special timing mat at the starting line and then records when you cross a similar timing mat at the finish line. So if it takes you 10 minutes to get across the starting line, that amount of time won't be counted in your overall net time.

Your official time will be the exact time it took you to get from the starting line to the finish line.

B-Tags can also be used to track where participants are on the course, as they run across timing mats at checkpoints on the course. Your friends and family members can track your progress on the course using the race website or by receiving text messages on their mobile device.

B-Tags have been replacing the old timing chips, which used to be the most popular method of timing and tracking runners. Unlike timing chips which are attached to the runner's shoe, the B-Tag is usually part of the race bib.

It's a strip of plastic either on the back or bottom of the bib. When putting on your race bib, make sure that you don't assume the B-Tag is an unnecessary part of the race bib and tear it off. You don't need to return the B-Tag at the end of the race—you can keep it since it's part of your race bib.

Tips for Accurate Tracking

ChronoTrack, one of the companies that make B-Tags, advises the following, to ensure an accurate race time:

  • Make sure your race bib is clearly visible on the front of your torso.
  • Make sure your bib isn't folded or wrinkled.
  • Keep your bib pinned in all four corners.
  • Don't cover your bib with clothing, runner belts, or water bottles.
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