What is the Circumference of the Earth

When all the eight planets of solar system are arranged according to decreasing size, the planet earth stands fifth in the list. In simpler terms, the earth is the fifth largest planet. But, if you consider only the terrestrial planets, it is the larger than the remaining three planets, viz. Mercury, Venus and Mars. The size of earth is determined from its circumference.

Circumference of Earth

While calculating the circumference, the correct shape of the object is considered. Thus, the circumference formula of a circle differs from that of an ellipse. Considering the massive size of earth, it is not practical to measure the diameter for calculating circumference. So, how to calculate earth's circumference? The circumference of earth was estimated for the first time by Eratosthenes (276-195 BC), a Greek astronomer, geographer and mathematician. The result (approximately 46,250 km) was close to the modern calculated value for circumference of earth (approximately 40,075 km).

The method adopted by Eratosthenes for calculating earth's circumference was relied on two presumptions, the first was round shape of the earth and second assumption was parallel ray of the sun. Even you can find out earth's circumference by conducting a simple experiment in one of the two equinox times of the year. You need to know rough distance between you and equator, and the length of a shadow. So while measuring the earth's circumference, you will get two different values - one for measurement at the equator and the other for circumference measured from the pole.

Circumference of Earth in Different Units

In geography, the shape of earth is defined as ellipsoid or oblate spheroid, meaning the diameter of the earth measured at equator (12,756.1 km) is slightly more than the value depicting the distance from north to south pole (12,713.5 km). In short, the diameter of the earth is not the same everywhere. Hence, if you see the earth's picture published in geological reports, you will notice that it is slightly bulged at the equatorial portion. Since diameter is more at the equator, the resulting circumference value is more, and vice versa. For your reference, circumference of our planet in different units are discussed below.

Centimeter: Needless to say, the estimated value for earth's circumference in cm is very large, approximately 4,007,500,000 centimeters. For converting cm to standard unit meter, 1 cm is equal to 0.01 m.

Circumference of the Earth in Feet: It is 131,477,280 feet wherein 1 foot is equal to 0.3048 meter.

Circumference of the Earth in Meters: When represented in the standard unit for length (meter), the circumference of earth is 40,075,000 meters. You can make a comparison between the values of earth's circumference in varied units.

Circumference of the Earth in Km: You might be already aware that 1 km is equal to 1000 meter. When measured at the equator, the earth's circumference is 40,075.16 km; while the value measured between the north and south pole is smaller, 40,008 km.

Circumference of the Earth in Miles: The earth's circumference in miles is 24,901.55, when measured at the equator. Whereas, when measured through poles, it is 24,859.82 miles. Remember that 1 mile is equal to 1,609.344 meters.

This was an overview information about calculating earth's circumference from equator and value of the same. In order to calculate the same from different latitudes, the formula '(Measured angle) / 360º = Distance from Equator / Circumference' is used. With this, I hope you are now clear about the earth's circumference and the methodology involved in measuring the same.