Spinning at a Thousand Miles an Hour

I'm currently sitting in London, spinning at 640 miles per hour. 

My friend Sofía lives in Quito, Ecuador, and because of the equatorial speed bonus, she’s currently spinning much faster than me - at 1,037 mph.

The Earth rotates once every 24 hours (roughly), and we all rotate with it. The circumference at the equator is about 24,901 miles, so at the equator, you're spinning at about 1,037 mph:

24,901 ÷ 24 hr = ~1,037 mph

But this speed decreases as you move toward the poles. The speed you're traveling is determined by your latitude, because - unless you live at the equator - you're moving in a smaller circle.

London is around 51.5° North, so I can calculate my rotational speed with this formula:

        Speed = equatorial speed × cos(latitude)

So:

        Speed = 1,037×cos(51.5)

        cos ⁡(51.5) ≈ 0.623 

        Speed = 1, 037 × 0.623 ≈ 646 mph

To calculate your speed, just plug in your latitude using the same formula.

Or you could just use the Earth Surface Rotatio Speed Calculator. 

Enter your location into this interactive map, and you won’t need to do any math - this map will automatically show you your tangential speed based on where you live.