A student in London at latitude 51.5 degrees N learns they are spinning at about 1,041 km/h right now, just by standing still. That is faster than a commercial jet cruising at 900 km/h. The calculator shows this instantly by entering 51.5 in the latitude field.
A physics teacher in Mumbai at latitude 19 degrees N uses the tool to show students that they are moving at 1,587 km/h, which is 1.29 times the speed of sound. The class then compares this to someone in Reykjavik at 64 degrees N, who is only moving at 734 km/h.
A space enthusiast planning a trip to the Kennedy Space Center at latitude 28.6 degrees N checks why launch sites are near the equator. The calculator shows 1,470 km/h at that latitude, confirming that equatorial launches get a bigger boost from Earth's rotation.
A trivia fan in Quito, Ecuador, at latitude 0 degrees discovers they are moving at the full equatorial speed of 1,674 km/h. They share the result on social media: "I am moving faster than the speed of sound right now."
Earth completes one full rotation relative to distant stars in 23 hours, 56 minutes, and 4 seconds. This is called a sidereal day. The calculator uses this period, not the 24-hour solar day, because the solar day includes extra rotation to compensate for Earth's movement along its orbit.
At the equator, you travel the full circumference of Earth (about 40,075 km) in one sidereal day. Dividing 40,075 by 23.934 hours gives 1,674 km/h. At any other latitude, the circle you travel is smaller. The radius of that circle is Earth's equatorial radius multiplied by the cosine of your latitude.
The formula is: speed = (2 x pi x radius x cos(latitude)) / sidereal day. At 45 degrees, cos(45) is about 0.707, so the speed is 70.7 percent of the equatorial speed, or about 1,184 km/h. At the poles, cos(90) is zero, so the rotational speed is zero.
On top of rotation, Earth orbits the Sun at about 107,000 km/h. The Sun itself orbits the center of the Milky Way at about 828,000 km/h. Adding all three gives your total speed through the cosmos, which exceeds 900,000 km/h no matter where you stand on Earth.
Input
Latitude: 0 degrees (Equator, Quito)
Output
1,674.4 km/h, 1,040.6 mph, 465.1 m/s, 100% of equator, 135.6% of speed of sound
Maximum rotation speed on Earth
Input
Latitude: 51.5 degrees N (London)
Output
1,041.7 km/h, 647.3 mph, 289.4 m/s, 62.2% of equator, 84.4% of speed of sound
Slower than the speed of sound
Input
Latitude: 40.7 degrees N (New York)
Output
1,271.5 km/h, 789.9 mph, 353.2 m/s, 75.9% of equator, 103.0% of speed of sound
Faster than the speed of sound
Input
Latitude: -33.9 degrees (Sydney)
Output
1,391.4 km/h, 864.4 mph, 386.5 m/s, 83.1% of equator, 112.7% of speed of sound
Southern hemisphere, same formula applies
Input
Latitude: 90 degrees (North Pole)
Output
0.0 km/h, 0.0 mph, 0.0 m/s, 0% of equator, 0% of speed of sound
You are just spinning in place
Things to keep in mind
How fast does the Earth rotate at the equator?
The Earth rotates at about 1,674 km/h (1,040 mph or 465 m/s) at the equator. This is calculated by dividing Earth's equatorial circumference (about 40,075 km) by the length of a sidereal day (23.93 hours).
Why does rotation speed change with latitude?
Earth's rotation speed decreases as you move away from the equator because the circle you travel in a day gets smaller. At latitude 45 degrees the speed is about 1,184 km/h. At the poles it is effectively zero because you are just spinning in place.
What is a sidereal day and why is it different from 24 hours?
A sidereal day is the time Earth takes to complete one full rotation relative to distant stars, which is 23 hours, 56 minutes, and 4 seconds (23.934 hours). A solar day is 24 hours because Earth also moves along its orbit, so it needs to rotate a bit extra for the Sun to appear in the same position.
How fast is Earth moving around the Sun?
Earth orbits the Sun at about 107,000 km/h (66,600 mph). This is much faster than the rotation speed at any latitude. The orbital speed is nearly constant because Earth's orbit is close to circular.
How fast is the Sun moving through the Milky Way?
The Sun orbits the center of the Milky Way at about 828,000 km/h (514,000 mph). Combined with Earth's orbital speed and rotation, you are moving through space at over 900,000 km/h right now.
Why don't we feel the Earth spinning?
The rotation is constant, so there is no acceleration to feel. The centrifugal effect from rotation is tiny compared to gravity. At the equator, centrifugal force reduces your effective weight by only about 0.3 percent.
Does Earth's rotation affect rocket launches?
Yes. Launching eastward from near the equator gives rockets a free speed boost from Earth's rotation. This is why the Kennedy Space Center at 28.6 degrees N and the Guiana Space Centre at 5 degrees N are located as far south as they are in their respective countries.
The rotation speed is calculated using a spherical Earth approximation with the WGS-84 equatorial radius. Earth is actually an oblate spheroid, so the true speed at a given latitude may differ slightly. The orbital and galactic speeds are approximate averages. The speed of sound varies with temperature and altitude.