The main famous “Derby” most people mean is the Kentucky Derby horse race. That race is 1¼ miles long and usually takes about two minutes to run, which is why it’s nicknamed “the most exciting two minutes in sports.”

However, “derby” can refer to several different events:

  • Kentucky Derby (USA, horse racing)
    • Distance: 1¼ miles (10 furlongs).
* Time: Roughly 2 minutes for the winning horse.
  • Epsom Derby (UK, horse racing)
    • Course length: About 1½ miles (1 mile, 4 furlongs, 6 yards).
* Winning times: Typically around 2½ minutes, depending on conditions.
  • Roller derby (contact sport)
    • Match length: Common modern format is 60 minutes of play, split into two 30‑minute periods.

If you tell me which derby you care about (Kentucky Derby, Epsom Derby, football derby, roller derby, etc.), I can narrow it down specifically to that event.