# Methods to determine the size of an object in microns

From OpenWetWare

### Mathematically

Pixels on our CCD are 6.45um. The size (in microns) of one pixel in an image will depend on how much the image was magnified before reaching the CCD:

**Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://api.formulasearchengine.com/v1/":): {\displaystyle \mbox{Pixel size} = \frac{6.45um}{\mbox{total magnification}}}**

Assuming that the magnifier is at position 1x (not 1.5x), this formula gives us:

60x : 0.1075 um/pixel or 9.30 pixels/um 40x : 0.1613 um/pixel or 6.21 pixels/um 20x : 0.3225 um/pixel or 3.10 pixels/um 10x : 0.645 um/pixel or 1.55 pixel/um