Density of an object is defined as mass per unit volume. Density - mass/volume (m/v) To find the density of a liquid using a graduated cylinder, you first of all take a measurement of the mass of the empty graduated cylinder (m1) and write it down. Lets say the mass is 0.5 kg (500 grams) Then fill the cylinder with the liquid that you want to find the density for and note down the volume (v). For easier calculation take 1 liter of the liquid. Now take a measurement of the mass of the cylinder with the liquid (m2) in it and write it down. Subtract the mass of the empty cylinder from the mass of the cylinder and liquid combined to get the mass of the liquid (m = m2 - m1). Now divide the result z by the volume (v) of the liquid. density = m/v