7000ft is WAYYY off. Given that the trailhead elevation is 8360ft and the summit is 14505ft, you have a net gain of 6145ft. Add in elevation losses that must be regained such as the drop into Bighorn Sheep Park and the drop after Trail Crest, and 6400ft of elevation gain looks about right.
Matt, you are overlooking the fact that you lose the gain twice. One on the way up, and once again on the way down. 7K may not be "exactly" right, but very close. Trail Crest is 13,600 +/-, Intersection with Muir Trail is at 13,400 +/- two ways = 400', Outpost camp not much, but many small up's and downs adds another 200' each way, so 400'. Those two issues account for additional 800', so conservative estimate would be 6145 + 800 = 6945. Also, not likely you parked level with trail head, so add a bit more, and Shazam, you get pretty much at 7K'. That is what my Garmin indicated the last time I hiked the main trail.
Also, see Bob's post above. His is likely more accurate. If so, roundtrip would get WAYYY over 7K:-)
