The volumes stamped on the sides are approximate and accurate to within about 5%. Graduated cylinders are useful for measuring liquid volumes to within about 1%. They are for general purpose use, but not for quantitative analysis. If greater accuracy is needed, use a pipet or volumetric flask. read more
Much better than that is a graduated cylinder. A graduated cylinder, while somewhat less accurate than a volumetric flask does have the advantage of being able to measure different volumes, whereas a volumetric flask is designed to measure one and only one volume. read more
When measuring liquids in a graduated cylinder, you always measure from the center of the curvature in the liquid called the meniscus. Some liquids, like mercury, have a convex meniscus. Most liquids, however, will have a concave meniscus and the volume in the graduated cylinder should be read from the bottom center of this meniscus (as above). read more