You weigh less on the equator than at the North or South Pole

4 minute read

You weigh less on the equator than at the North or South Pole, but the difference is small. Remember that your body has not changed. On the contrary, the gravitational force and other forces, as they approach the poles. These forces change immediately when you return to your original latitude. In short, a trip to the equator is not a long-term weight-loss program.

Your weight is the combination of all large-scale long-term forces in your body. Although the Earth’s gravitation is the strongest large-scale force, it is not the only one. What you experience as toplam something that pulls you down sadece is in fact the sum of all forces, not just gravity. Four dominant large-scale, long-term forces:

  • Gravity of Earth
  • Gravity of Sun
  • Gravity of Moon
  • Centrifugal force of Earth


Remember that although the Coriolis force in the world plays an important role in shaping hurricanes and ocean currents, it does not contribute to your total weight as it is not a static force. Also, when driving a roller-coaster, a lift, a swing, or other vehicle, additional forces arise, but these forces are temporary, so they don’t contribute to your overall long-term weight. Finally, the electromagnetic and nuclear forces are either very small-scale or too short to contribute to your total weight.

For our purpose, we want to think about the forces that differ significantly in the equator against the poles. Although the sun’s gravity is strong enough to keep us and the earth in orbit, the position of the sun is constantly changing according to a point on the equator. As a result, within a few days, the sun’s gravitational force at a point on the equator is the same as the gravitational force of the sun at a point above the poles. The same applies to the month. This leaves only gravity and the Earth’s centrifugal force as two forces that contribute to your weight, which differ in the equator against your poles.

As we learned in high school, the Earth’s gravity is almost constant all over the earth. But this is just an approach. If the world were completely spherical and its intensity was exactly equal, the power of the earth’s gravity would be exactly fixed at all points on its surface. But it is not. There are three major complications in the Earth’s gravitational field. First, it is not a world globe. The world is spinning, throwing a little flattened, like a pizza container thrown into the air. As a result, the world is not an oblate spheroid and an excellent sphere. If you stay at the sea level in the equator, you are 6378 km from the center of the world. On the contrary, each pole is only 6357 km from the center of the world. The force of gravity weakens as it moves away from a gravitational body, the points on the equator are longer, and there is weaker gravity than the poles. Two other complications in the world’s gravitational field; local surface mass variations such as unequal internal density and mountains; They’re small enough to neglect them here. Therefore, assuming that the entire mass of the earth is in the center, we can calculate the force of gravity in the equator and in the poles. Using Newton’s law of gravity, we can see that the force of your body’s gravitational force on the equator is 9.798 m / s2, and the mass of your body is 9.863 m / s2.

The centrifugal force of the world also varies with latitude. The centrifugal force is the external force felt when you are in a rotating reference frame. While the centrifugal force is ultimately a non-essential force caused by the inertia of the bodies, your body is very real for the body in a rotating reference frame as it is on the rotating earth surface. The centrifugal force is proportional to the tangential velocity of the rotating reference frame. The Equator is moving quickly as the rotation of the earth, so there is too much centrifugal force. On the contrary, the poles do not rotate at all, so they have zero centrifugal force. Since the centrifugal force points outwards from the center of rotation, it tends to cancel some of the gravity. If the world wasn’t turning, you’d feel a full gravitational force. Since there is more centrifugal force in the equator to cancel gravity, the total weight in the equator at the poles is even less. The centrifugal force on the equator in your body is 0.034 m / s 2 times the mass of your body. The centrifugal force in the poles is zero.

Your total weight at the sea level in the equator (gravity minus centrifugal force) is therefore 9.764 m / s 2 times your mass, while your weight is 9.863 m / s2 in the mass of the poles. If we use a more accurate model (taking into account the shape of the continents) these numbers will be slightly different, but the overall point will be the same: you weigh 1% less than the poles at the equator. If you weigh 200 pounds (90.7 kg) at the North Pole, you will have 198 pounds (89.8 kg) of weight on the equator. Note that we focus on the equator and poles as extremes, but the same effect is at all latitudes. As Mexico City is closer to the equator, in Mexico City, you weigh less than New York City.