Distance: 2.6 miles (4.2 kilometers) round trip
Elevation at trailhead: 4,400 feet (1,340 meters)
Elevation at Inspiration Point: 5,390 feet (1,643 meters)
Total Elevation Gain: 990 feet (300 meters)
These satellite photos always look flat, but there's a thousand feet of elevation change between the trailhead (4,400 feet) and the Merced River just to the north (3,400 feet), and another thousand feet between the trailhead and Inspiration Point, which is at the left end of the squiggly red line.
The trail that crosses the Inspiration Point route about halfway up is the old stagecoach road into Yosemite Valley. If you take it downhill, it'll lead you past Artist Point and eventually to the Bridalveil Fall parking area.