Why Is a Marathon 26.2 Miles? The Honest Answer Is That Nobody Knows

The part that is documented

On the final day of the 1908 London Olympics, the marathon was run from the East Lawn of Windsor Castle to White City Stadium in Shepherd’s Bush, finishing with 385 yards on the stadium track.

The races that now define the distance are covered in the World Marathon Majors.

The distance was 26 miles 385 yards — 42.195 km.

That much is solid. Everything after it is where the story usually goes wrong.

The explanation everyone gives

You will read, more or less everywhere, that the British royal family asked for the start to be moved to Windsor Castle so the royal children could watch, and that the extra 385 yards was added so the race would finish in front of the royal box.

It is a wonderful story. It is repeated by major reference works and by the sport’s own popular histories.

It is not documented.

The detailed account of the 1908 race states plainly that the reason for the distance is unknown, and notes that the IAAF’s minutes are reportedly silent as to why 26 miles 385 yards was chosen when the distance was adopted. It records that Queen Alexandra presented Dorando Pietri with a commemorative cup after his disqualification, and that the Princess of Wales watched the start — but it makes no claim that anyone requested the distance.

So the most-repeated fact about the marathon is an explanation with no surviving source behind it.

Before 1908, there was no marathon distance

This is the context that makes the whole question make sense, and it is usually skipped.

For roughly the first 25 years of the modern marathon, the race had no fixed length. Commonly cited figures for the early Games:

Games	Distance (commonly cited)
1896 Athens	~40,000 m
1900 Paris	40,260 m
1904 St Louis	40,000 m
1906 Athens (Intercalated)	41,860 m
1908 London	42,195 m
1912 Stockholm	40,200 m

These are given as commonly cited rather than settled — sources disagree on individual figures, and notably on the 1920 Antwerp distance, where reputable accounts differ by around two kilometres.

But the point that matters is not in dispute: a marathon was simply “about 40 kilometres”, measured differently in each city. The 1908 figure was not a considered standard. It was one course, in one place, in one year.

How one course became the world’s

The distance was adopted as the official marathon length by the IAAF — now World Athletics — with 1921 the year usually given, though some sources date standardisation to 1924, the first Games at which the distance applied. That disagreement is itself worth noting rather than papering over.

What can be said is that by the time the decision was taken, the 1908 distance had already established itself worldwide through use. It was not selected on merit. It won by circulation.

Once fixed, it became one of the most consequential arbitrary numbers in sport. Every marathon world record, every qualifying standard, every training plan is calibrated to a figure produced by where a race happened to start and finish in west London in 1908.

And Pheidippides did not run it

The founding legend — a messenger running from Marathon to Athens to announce victory and dying on arrival — is legend, not documented history, and the accounts of it appear centuries after the supposed event.

More importantly for this page: even taken at face value, it has no connection to 26.2 miles. The modern distance was produced by a measured route in England in 1908, not by any ancient run. The name was borrowed; the number was not.

This is the same pattern that runs through the founding of the Olympic Games, where the IOC’s own position is that the founding date is unknown and 776 BC is merely the first written mention, and through when football was actually established, where the tidy explanations in circulation turn out to be later reconstructions.

What to say when someone asks

The distance is 26 miles 385 yards because that is what the 1908 London course measured, and that course’s figure spread until a governing body ratified what was already happening.

Why the 1908 course was that length is not recorded. The royal-box explanation may well be true. It is simply not evidenced, and the body that adopted the distance left no reason in its minutes.

That is a less satisfying answer than the one in circulation. It is the one the record supports.

More origin questions are in sports history, and the sport’s other most-cited numbers in the fastest 100m sprinters.