Epworth Sleepiness Scale
A short questionnaire that asks how easily you doze off in ordinary situations during the day.
A little more detail
A self-report scale developed by Johns in 1991 that scores the chance of dozing in eight situations from 0 to 3; the total ranges from 0 to 24. In the study by Johns and Hocking, the scores of people without a sleep disorder stayed between 0 and 10, and above 10 was taken as excessive daytime sleepiness. It is licensed; it does not diagnose, it only rates subjective sleepiness.
Source: Johns MW. A new method for measuring daytime sleepiness: the Epworth sleepiness scale. Sleep. 1991;14(6):540-545. doi:10.1093/sleep/14.6.540; Johns M, Hocking B. Daytime sleepiness and sleep habits of Australian workers. Sleep. 1997;20(10):844-849. doi:10.1093/sleep/20.10.844