How long is a marathon, and why that number?
26.2 miles, precisely 42.195 kilometers. The legend behind the event: the Greek messenger Pheidippides running from the plain of Marathon to Athens in 490 BC to announce victory over Persia, then dropping dead, a story historians treat with heavy skepticism but the sport keeps anyway.
The oddly specific distance is British. Early Olympic marathons were roughly 25 miles, but the 1908 London Games routed the course to start beneath the windows of Windsor Castle and finish in front of the royal box at the stadium, which measured out to 26 miles 385 yards. The number stuck, and in 1921 it was adopted as the official standard. Every runner hitting the wall at mile 25 is, in a real sense, suffering for royal sightlines.
Adjacent numbers: a half marathon is 13.1 miles, a 10K is 6.2, a 5K is 3.1, and typical first-timer finishing times run four to five hours, Pheidippides having set an unfortunate precedent for pacing.
26.2 miles, standardized because the 1908 London Olympics stretched the course so the race could start at Windsor Castle and finish in front of the royal box. Runners suffer for that extra 1.2 miles to this day.
- World Athletics
- Boston Athletic Association historical resources
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https://frequentlyaskedquestions.us/q/how-long-is-a-marathon/Everybody Asks. (2026, July 28). How long is a marathon, and why that number? https://frequentlyaskedquestions.us/q/how-long-is-a-marathon/“How long is a marathon, and why that number?” Everybody Asks, 28 July 2026, https://frequentlyaskedquestions.us/q/how-long-is-a-marathon/.“How long is a marathon, and why that number?” Everybody Asks. Last modified July 28, 2026. https://frequentlyaskedquestions.us/q/how-long-is-a-marathon/.This page summarizes the primary sources listed above. For academic or encyclopedic work, cite those primary sources directly wherever possible.