Upcoming 100Ks

Endurance Grid lists sixty-one 100Ks across the US, from September 2026 to November 2027 across 24 states.

61
Races
24
States

What a 100K is

A 100K is a running race where athletes run 62.1 miles long (100 kilometers) for time.

100Ks are busiest in October and May, with the most in Texas, Pennsylvania, Connecticut, and New Jersey.

Frequently Asked Questions

How many 100K running races are there in the US?
Endurance Grid's Race Calendar lists 61 upcoming 100K running races across 24 states.
How far is a 100K running?
A 100K is a running race where athletes run 62.1 miles long (100 kilometers) for time.
Which states have the most 100K running races?
The states with the most 100K running races on Endurance Grid's Race Calendar are Texas, Pennsylvania, Connecticut, New Jersey, Colorado, and Utah.