Semen is a fluid that contains sperm and fluids from the prostate, seminal vesicles, and bulbourethral glands. It helps sperm travel to an egg for fertilization.

Pondering sperm and semen and wondering how they differ? We’ll cover that and answer some of your other burning questions here.

Nope! (Mind blown, right?)

Semen and sperm are kinda like squares and rectangles. Sperm is a part of semen, but semen isn’t a part of sperm.

Semen, also called ejaculate or cum, is the whitish fluid that comes out of the penis when a person comes — well, usually, but not always. (You can read more on dry orgasm here if you’re curious.)

Sperm are male reproductive cells and are just one component of semen, though a very important one if you’re looking to reproduce.

Who knows for sure? But it’s easy to see why people do it.

I mean, both come out the same place, after all. And both words contain five letters and start with the letter ‘S’.

It’s an honest mistake.

Yep! Semen is actually a combination of mature sperm and fluids from the prostate, the seminal vesicles, and bulbourethral glands.

This cocktail is chock-full of ingredients, including sugars, proteins, and even some vitamins and minerals.

You know how sperm cells are shaped like tadpoles and often referred to as “swimmers”? Yeah, no.

Despite their wiggly tails and fish-esque appearance, without the help of semen to carry them, sperm would just keep swimming in circles.

Semen is essentially the tailwind that helps sperm get to the egg for the purpose of procreation.

The making of semen is actually a big and pretty impressive production.

Semen is formed in a few different places:

  • Testicles. The testes — aka the balls — are two small organs that sit inside the scrotum and make sperm and testosterone.
  • Epididymis. This long tube is located near each testicle and moves the sperm from your danglers to the vas deferens.
  • Vas deferens. This tube connects the epididymis and urethra, which is the hole that urine and semen exit the body through. The vas deferens stores sperm and carries it out of the scrotum.
  • Seminal vesicles. These sac-like glands sit behind the bladder and produce seminal fluid that forms part of semen.
  • Prostate. The prostate is a gland that surrounds the neck of the bladder and urethra and secretes an alkaline fluid that forms part of semen. It also helps propel semen from the penis.

Once semen is made, it passes through the urethra and out of the penis during ejaculation.

On average, around a teaspoon’s worth, but there are a few things that affect this.

Factors like smoking, diet, genetics, and overall health can impact semen volume.

If a person with a penis goes a few days without sex, they’re likely to ejaculate more. Age is another big factor.

Fun fact: Those with penises produce the most semen in their early 30s.

Not usually, but it can.

If there’s sperm leftover in the urethra, it can get mixed in with pre-ejaculate, or pre-cum, if you prefer.

This is why the pull-out method isn’t considered a reliable form of birth control.

In various studies, samples of pre-ejaculate have been shown to contain active, mobile sperm.

Only if you’re looking through a microscope.

Sperm are tiny. Like really tiny.

The average sperm measures just 4.3 micrometers (μm) long and 2.9 μm wide.

From 15 million sperm to over 200 million sperm per milliliter (ml) of semen is considered a normal sperm count.

Lots of things can affect sperm count, from problems anywhere along the reproductive system to medical conditions to lifestyle, even a person’s environment.

It depends on where it lands once it leaves the body.

Sperm that make it into the warmth and safety of a vagina can live up to 5 days thanks to the protective effects offered by cervical mucus.

For sperm that land elsewhere, the chances of a long life are pretty dismal — usually only a few minutes, especially if they land on a cold, dry surface, like the bathroom floor or computer screen.

Hot water can kill sperm even faster.

The body is like a sperm assembly line, always making new sperm.

The entire process, from germ cell to mature sperm takes around 74 days.

Nope. A penis haver’s body continues to make sperm as long as they’re alive.

That said, quality and motility decline over time, especially after the age of 50.

People will likely forever use the words semen and sperm when referring to ejaculate, but you, smarty-pants, now know they’re not the same.