Direct answer
A circulating red blood cell is typically about 6–8 µm wide; ScaleTrip uses 7.5 µm as a representative diameter. It is a flexible biconcave disc, not a rigid sphere.
Representative value7.5 µm
In meters7.5 × 10⁻⁶ m
Measurement typeTypical diameter
Put it in context
What are we measuring at this scale?
The comparison uses width across the cell. Thickness is a different dimension, so it should not be substituted for the displayed diameter.
Conceptual visualization
Red blood cell
A flexible biconcave disc roughly six to eight micrometres wide.
Source and verification
Where the value comes from
NCBI Bookshelf — Red Blood Cell Membranes
ScaleTrip keeps the 6 µm–8 µm range and the typical diameter label visible together.