Currently, 6.5 miles one way. Due to various office moves, I've also had commutes of 9, 5, and 3.5 miles.

But a key factor is also

**how often** you commute by bike. While I was able to do that 9 mile commute fairly regularly (probably averaging 2-3 times a week throughout the year), I definitely did the 3.5 mile commute more frequently. And I'm pretty sure that's the case with most people: as one-way mileage goes up, frequency goes down.

So perhaps total yearly commuting mileage is the most informative number. I linked to

this thread at BikeForums before, but now I actually threw the data in a spreadsheet to calculate some numbers. From that group of 130 members of a bike-commuting forum who cared enough about their bike-commuting mileage to track it an post it on the Internet in 2011, we get:

Average total mileage: 1967

Median total mileage: 1283

If we assume full-year commuting (5 days a week for 48 weeks (52 - 4 weeks vacation/holidays)), the average one-way commute is 4.1 miles, and the mean is 2.7 miles.

If we pick a "minimal frequency" (perfect weather only?) extreme (2 days a week for 30 weeks), the average is 16.4 miles, and the mean is 10.7.

Said another way, if you ride to work every single day, you're more badass than half of all bike commuters if your one-way commute is more than 2.7 miles. Or, if your one-way commute is 10.7 miles, you're more badass than half of all bike commuters if you can do it more than 60 times in a year.

In your specific case of a 9-mile commute, if you did that every day of the year, that would be 4320 miles, putting you in the 86th percentile. Doing it twice a week year-round would put you in the 56th percentile.