This page is mirrored by permission
from Jim Sullivan, creator of this page and the Cells
Alive! web site.
How Big is a ... ?
This animation can
for classroom use.
head of a pin is about 2mm in diameter. Use this animation to
compare the relative sizes of cells and organisms. Nearly invisible
without magnification, dust mites dwarf pollen grains and human
cells. In turn, bacteria and viruses are even smaller.
the left and right arrows to change magnification.
on the magnifications (1, 10, 100...) for a "Power of Ten"
an individual cell or organism (right) to bring it into view.
the scale to measure individual cells.
millimeter = 0.001 meter 1
micron = 0.000001 meter
1 nanometer = 0.000000001 meter