In a calibrated eyepiece graticule, a single division measures 2.5μm.

The graticule is 100 divisions long and each division is 2.5 micrometres. Measured against it on the drawing, the nucleus (the small dense oval near the right-hand wall) spans about 6 divisions, so its size is about 6 x 2.5 = 15 micrometres. The whole cell spans about 96 divisions (240 micrometres), which is the 230 micrometre distractor.