I had a commute that was about 13.2 miles (21 km) each way. It took a lot of energy from me so I only did it two or three days a week. Usually, I did it on a road bike with drop handlebars and more gears than I needed. It also had a rack and fenders. Sometimes I used a backpack and sometimes panniers.

To me, the ideal commuting distance is between 3 and 7 miles. When it's under 7 miles, I might wish for the ride to be over soon but it's never terribly burdensome. And right m commute is slightly under 4 miles, and I'm quite happy about that. I'm in New York City, so my alternate mode is the subway which is reliable. I'm very grateful I don't have to commute by car. In my last job search, I set a commuting time limit of 60 minutes by either bike or subway. I do not plan to buy a car.