1 mile = 1760 yards = 5280 feet = 63360 inches
1 mile = 1.60934 km = 1609.34 m = 160934 cm
In mathematical terms this is a no brainer.
As a practical application, related to hiking, the above info is mostly useless.
I hiked both, Saturday and Sunday this weekend.
Saturday's hike was 11 miles round trip and we climbed 2257 feet over 5.5 miles.
Today's hike was "only" 9 miles round trip with a gain of 3220 feet over 4.5 miles.
Which one do you think was the tougher hike?
Surely the shorter one.
But not just elevation is the decider whether you're doing an easy mile or a hard mile. Terrain is another variable. Nice forest path vs. loose rock for example. And what about temperature? Extreme heat drains your energy quickly.
Turns out, of course, that Saturday's longer hike also had the smoother trails and lower temps, which made today's hike, with temps in the 90s, very tough, though beautiful.
Saturday's hike: Islip Saddle (6593') to Mt. Islip (8250') to Mt. Hawkins (8850')
The trail follows the Pacific Crest Trail.
Today's hike was local in our San Gabriel Mountains. Chantry Flat (1760') over Winter Creek Trail to Manzanita Ridge (4980')
In conclusion: One Mile ≠ One Mile
Just like one pound ≠ one pound. But you already knew that.