Identify the correct dosage of medication: Injectable medicines are usually measured in milliliters (ml). The syringe is marked in increments of a ml, such as 0.2 ml, 0.4 ml and so forth. To measure the dosage with the syringe, look directly at the top edge of the black plunger tip. Check your knowledge of syringe markings with your healthcare provider. To measure the dosage with the syringe, look at the top edge of the plunger tip. See that it is even with the line for your dose. Mark the dosage on the syringe.