# How Fast Can a Human Go?

(Last Updated On: August 11, 2022)

## How Fast Can a Human Go?

Alright, just to set expectations, we’re going to talk about this in terms of the human body. You know, our legs. But there is more than one way to take this question. We can also shoot ourselves around in planes and rockets, which is something we’ve done before. So maybe we should answer the question in multiple senses. So let’s get into it–how fast can a human… go?

## How Fast Has a Human Ever Gone?

If you’re wondering, the fastest spaceflight we could find was Apollo 10, which ended up topping out around 25,000 miles per hour (40,000 km per hour). Those speeds were reached when its crew were on their way back to Earth in 1969, which was basically a trial run for the first moon landing two months later.

Outside of flying around in space or the SR-71 Blackbird, we also have the fastest pair of human legs. The SR-71, by the way, can hit speeds of 4,500 miles per hour (7,300 km per hour). That’s all despite the fact that it’s actually Cold War Era, so we guess planes didn’t really have to get faster, unless there’s something that us normie civilians don’t know about.

As far as us people go, you’ve likely heard of Usain Bolt, who has the fastest 100 meter dash. Around 27.5 miles per hour (~43 kilometers per hour).

## How Fast Could a Human Go (In a Plane)?

There is very much an upper limit to how fast you could go, and you might want to start with the idea of g-force. That basically means you’re accelerating equal to faster than the acceleration of gravity (9.8 meters per second squared). Because we’re all on Earth, we perpetually exist at about 1 G. The average person can sit through up to 5 Gs, which you could experience by taking a trip on a roller coaster.

If you want to fly the big planes and spaceships, you’ll have to train to take up to 9Gs. Which, roughly, means you’d briefly experience life where you were on a planet 9 times heavier than Earth.

Pushing yourself farther than 9 Gs gets into some shenanigans. Blood stops being able to flow properly, and you’ll go unconscious. Then you’ll probably die. Unless you’re John Stapp, who very briefly survived a stint of 40 Gs.

The thing about g-force is that it’s acceleration. You’re speeding up. So what’s the upper limit of just straight up… speed?

Well that’s just semantic, since what kills you isn’t actually your speed. It’s the change in speed that kills you when you’re getting crushed by multiple Gs. The Earth is big, like 5,973,600,000,000,000,000,000,000 kilograms big. It spins fully once about every 24 hours. So the surface of the equator is moving about 1,000 miles per hour (1,600 km per hour). The big ball itself is also moving at about 66,600 miles per hour (107,000 km per hour) through space, rotating around the Sun. Don’t forget that the Sun is moving through the Milky Way, and Milky Way is straight zooming through the Universe.

But because we constantly live moving at those speeds, it’s not a big deal. It’s only a big deal when those speeds change by a lot, hence acceleration and deceleration.

As they always say, it’s not the fall that kills you. It’s the sudden stop.

Ouch.

## How Fast Can Our Legs Go?

Usain Bolt’s record is 27 mile per hour, but can humans go faster?

For a long time, we thought that the speed limit of the human legs was due to the impact of our feet on the ground. You know, you can only slam your legs against the ground so hard before they explode. Faster you sprint, the more force exerted onto your feet.

But it turns out that sprinters might not be slamming their legs into the ground at the human limit. So something else is limiting us. That limit rather seems to be how fast our muscles can contract instead.

A University of Wyoming study seemed to suggest that we could get a 40 mile per hour human. Seems like they did this by calculating how much force your legs could actually take–considering how sprinters aren’t wrecking their legs as hard as we used to think.

Of course, that didn’t take into account the speed at which our muscles can contract–something rightful skeptics of the 40 mile per hour human posited.

So, unfortunately, our speed limit is probably markedly less than 40 miles per hour. But it is something! So our top speed is just “less than 40 miles per hour” and “at least 27.”

So we know how fast our legs are, but what about your fingers? Test yourself here.