Here's a rough estimate:

* Red blood cells: About 4.5 to 5.5 million RBCs per microliter of blood.

* White blood cells: About 4,500 to 11,000 WBCs per microliter of blood.

This means there are about 1,000 red blood cells for every white blood cell!

While white blood cells are essential for our immune system, red blood cells are responsible for carrying oxygen throughout the body. They are much more numerous because their primary function is to transport oxygen efficiently, a task that requires a large number of cells to achieve.