How Weight and Mass Change on Mount Everest

Weight Decreases, Mass Stays Constant

If you travel to the summit of Mount Everest, your weight will decrease while your mass remains exactly the same. This distinction is fundamental to physics.

Understanding Weight

Weight measures the force exerted on an object due to gravity. It is calculated as mass multiplied by the acceleration due to gravity (W = m × g).

• At sea level: Gravity accelerates objects at approximately 9.8 m/s². A 100 kg person weighs 980 newtons.
• At Everest's summit: Being farther from Earth's center reduces gravitational acceleration to about 8.8 m/s². That same 100 kg person now weighs only 880 newtons—a reduction of roughly 10%.

Understanding Mass

Mass quantifies the amount of matter in an object. It is an intrinsic property that does not change with location, altitude, or gravitational field. The 100 kg person on Everest still contains the same amount of matter as at sea level.

Key Takeaway

Climbing Mount Everest makes you lighter in terms of weight, but your mass—your actual physical substance—is unchanged.