All things · Under the Microscope

Red blood cell: how big is it?

Red blood cell is about 7.5 µm. In everyday terms, that is ≈ 70,800 hydrogen atoms.

Size

7.5 µm

In metres

7.50 × 10⁻⁶ m

Everyday comparison

≈ 70,800 hydrogen atoms

Chapter

Under the Microscope

Did you know?

You have around 25 trillion of them, and each one lives for about 120 days.

How it compares

• About 3× bigger than Platelet (2.5 µm).
• About 1.6× smaller than White blood cell (12 µm).

Other things of a similar size

• E. coli bacterium 2 µm
• Platelet 2.5 µm
• White blood cell 12 µm
• Skin cell 30 µm
• Sunflower pollen 35 µm
• Human hair (width) 70 µm

Sizes are rounded, typical values drawn from standard reference sources, including NIST/CODATA physical constants and NASA's planetary fact sheets. Real objects vary; see About for how sizes are chosen.