How fast is the universe expanding in mph ?

Hint:The universe refers to all of space and time, as well as their contents, which include planets, stars, galaxies, and all other forms of matter and energy. The Big Bang theory is the most widely accepted cosmological explanation for the evolution of the universe. According to this theory, space and time coexisted \[13.799\pm 0.021\]billion years ago, and the universe has been expanding ever since.

Complete step by step answer:
The universe's expansion is the increase in distance over time between any two given gravitationally unbound parts of the observable universe. Formalized paraphrase It is a natural expansion in which the scale of space itself changes. The universe does not expand "into" anything and does not need space to exist "outside" of it.

Technically, neither space nor its objects move. The metric governing the size and geometry of spacetime itself, on the other hand, changes in scale. Objects move apart from one another at ever-increasing speeds as the spatial part of the universe's spacetime metric scales up. To any observer in the universe, all of space appears to be expanding, while all but the nearest galaxies recede at rates proportional to their distance from the observer – at great enough distances, the speeds exceed even the speed of light.

In theory, the expansion of the universe could be measured by taking a standard ruler and measuring the distance between two cosmologically distant points, waiting a certain amount of time, and then measuring the distance again, but in practice, standard rulers are difficult to come by on cosmological scales, and the timescales over which a measurable expansion would be visible are too large to be observable even by multiple generations of humans.

Currently, the rate is the Hubble constant.
\[{{H}_{o}}~=\text{ }68\text{ }km/s/megaparsec\]
\[\Rightarrow {{H}_{o}}=\text{ }152112\text{ }miles/h/megaparsec\]
\[\Rightarrow {{H}_{o}}=\text{ }0.152112\text{ }mile/h/parsec\]
\[\Rightarrow {{H}_{o}}=\text{ }7.374591\text{ }E-07\text{ }miles/h/AU\]
\[\therefore {{H}_{o}}=\text{ }3.063117\text{ }E-15\text{ }mile/h/mile\]
We have used, \[1\text{ }parsec\text{ }=\text{ }206265\text{ }AU,\text{ }1\text{ }AU\text{ }=\text{ }149597871\text{ }km\text{ }and\text{ }1\text{ }mile\text{ }=\text{ }1.609344\text{ }km\]

Note:There is no object in the Universe that is moving faster than the speed of light.The Universe is expanding, but it does not have a speed; instead, it has a speed-per-unit-distance, which is equivalent to a frequency or an inverse time.