The accuracy specification of graduated cylinders is taken as a percentage of the full scale, that is, the volume at the top fill line. For class B graduated cylinders, the stated accuracy of 1% means that a 100ml cylinder when filled correctly will be accurate to 100 ± 1ml.

In general, that accuracy will also apply down to the halfway fill mark so that at 50ml the error will be ± 0.5ml. However, at volumes below this, the error can increase significantly as the video explains.


The bottom line then is this:

If you need to measure out 5-10ml, buy a 10ml graduated cylinder.
If you need to measure out 12.5-25ml, buy a 25ml graduated cylinder.
If you need to measure out 25-50ml, buy a 50ml graduated cylinder.
If you need to measure out 50-100ml, buy a 100ml graduated cylinder.
If you need to measure out 125-250ml, buy a 250ml graduated cylinder.
If you need to measure out 250-500ml, buy a 500ml graduated cylinder.
If you need to measure out 500-1000ml, buy a 1000ml graduated cylinder.