Men ejaculate different amounts of semen. Normally, an ejaculation makes between 1.5 and 5 millilitres (up to one teaspoonful) of semen. More semen usually comes out if a man has not ejaculated for many days, or if he has been stimulated (made sexually excited) for a long time. Older men make less semen. If a man ejaculates an unusually small amount of semen, this is a medical condition called hypospermia.