Penises are twice the size people actually think they are

You might have done enough Googling and self-conscious measuring to think you know exactly what the average penis size is, but in fact you're probably underestimating by at least half.

What's the average penis size? You might have heard that it's around five inches if you listen to relatively reliable sources - if you've been hearing anything higher than six and a half, know you're either surrounded by some impressive specimens, or liars.

According to Lloyds Pharmacy's Online Doctor, the average length of an erect penis ranges from 4.7 to 6.3 inches around the world. When flaccid (we really should get a better name for that), the average length is between 2.8 to 3.9 inches.

So, when considering the studies that contribute to those figures, around five inches while erect isn't exactly wrong. However, this only accounts for what's outside the body.

Though it hangs loose and ready for action on the outside, the penis does actually have a lot going on inside, too.

The above video shared by TikToker Alice Williams has a good image to help you imagine what's going on, as she explains: "About half of the entire length [of the penis] is actually housed inside the body."

Though typically relatively straight on the outside, erect penises are actually shaped like a boomerang when taking into account the part inside the body.

Tobias Kohler, MD, assistant professor of urology at Southern Illinois University School of Medicine, told WebMD: "Most guys would be proud to know that their penis is twice as long as they think it is."

The hidden part of the penis includes the 'root', which is tucked up inside the pelvis and attached to the pubic bone.

That doesn't mean you can start going around telling people you're concealing 10 inches under your belt, though, because that hidden section isn't likely to make any appearances in the bedroom. As Williams points out, it needs to stay connected to the rest of the anatomy, so it's 'probably best it stays put'.

No matter the length, though, it's important that penises get to stand to attention regularly, as Kohler explains it has to be 'exercised' with erections to stay in shape.

The rush of the blood can help enrich the muscle with oxygen and therefore help maintain its health, and even if men find themselves in entirely un-erotic circumstances, Kohler has assured that the brain can lend a helping hand by causing a erections during sleep.