How Small Is A Human Cell?

Above me, you will see an image of a human cell. According to Google, there are over 100 trillion cells in the human body. It is very difficult to imagine how small a cell is, but there are measurement systems that help us understand the size of a singular cell.

The biggest cell in the human body are egg cells, and they are about 0.1 millimeters in diameter. The egg cell is the only cell in the human body that is visible without using a microscope, and they are also 10,000 times larger than a sperm cell. An egg cell is still very small, as they are very small compared to the things we see around us, like a penny. The image above shows 10 human egg cells in comparison to a penny.

On the other hand, sperm cells and red blood cells are the smallest cells in the human body. A sperm cell is only about 4 micrometers long, which is .004 or 1/250th of a millimeter. A red blood cell is similar in size, as they are about 5 millimeters in diameter. To put this into comparison, one drop of blood contains about 5 million red blood cells. In an average human body, there are 4.7–6.1 million cells per microliter, and there are about 5 liters of blood in an average human body. This means that each human has anywhere from 23.5 trillion to 30 trillion red blood cells in their human body.

I believe that these comparisons show how vast and amazing the human body really is because trillions of different structures are working together to power each and every human. Each cell works together to create tissue, which then creates an organ, which is a part of an organ system. Multiple organ systems working together then create an organism.

We talked about human cells, but what about other animals. How big can a singular cell actually become. Tune in tomorrow to find out what the largest cell on earth is.

Hint: It may be an egg