Altitude Difference: Mount Everest vs. Death Valley

Calculation

• Mount Everest summit: +29,028 ft (8,848 m) above sea level.
• Death Valley (Badwater Basin): −282 ft (−86 m) below sea level.

Difference = 29,028 − (−282) = 29,028 + 282 = 29,310 feet (8,934 m).

Perspective

That's ~5.55 miles (8.93 km) of vertical relief—greater than the cruising altitude of many small aircraft.