How long is a marathon? Exact distance in miles and kilometres
A marathon is 42.195 kilometres, or 26.2 miles. The distance is fixed worldwide. Anything shorter and the race does not legally count as a marathon.
The exact distance
A marathon is 42.195 km — exactly 26 miles and 385 yards (26.2188 miles). The distance was standardised at the 1908 London Olympics: the course was lengthened so the royal box at Windsor Castle could see the finish line, and the resulting 26 miles 385 yards became the official distance in 1921.
Every certified marathon course in the world matches this distance to within a tolerance of 0.1%. Race results from non-certified courses do not count for qualifying times (Boston, World Marathon Majors).
How long does it take to run?
For amateur runners, marathon finish times typically sit between 3h30 and 5h30. Sub-4 hours is a common goal; sub-3 hours is a competitive amateur time. The world record sits just over 2 hours.
Most first-time marathoners need 16 to 20 weeks of preparation, running 4 to 5 days per week, with long runs that peak at 30–35 km.
Marathon vs half marathon
A marathon is exactly twice the distance of a half marathon, but the difficulty does not double — it more than doubles. The body shifts from glycogen-burning to fat-burning around the 30 km mark, and the last 12 km of a marathon is qualitatively different from the same distance run fresh.
If you are choosing your first long-distance race, a half marathon is the safer entry. A full marathon usually requires a base of 6+ months of consistent running before training even starts.
Frequently asked questions
How many miles is a marathon?
A marathon is 26.2 miles, or precisely 26 miles and 385 yards (26.2188 miles), which equals 42.195 km.
How long is a marathon in kilometres?
A marathon is 42.195 km. The distance is fixed worldwide and certified by World Athletics.
Why is a marathon 26.2 miles?
The 1908 London Olympics set the distance at 26 miles 385 yards so the course could finish in front of the royal box at Windsor Castle. World Athletics adopted it as the official marathon distance in 1921.
How long does it take to run a marathon?
Amateur marathon times typically range from 3h30 to 5h30. Sub-4 hours is a common goal for trained recreational runners. World-class times are just over 2 hours.