Ticks vary in size depending on their life stage and whether they have fed. Generally, ticks range from about 1 mm to 1 cm in length

. Adult ticks are typically around 3 to 5 mm long but can become much larger when engorged after feeding, sometimes reaching up to 10 mm (1 cm)

. More specifically:

• Larvae are very tiny, about the size of a grain of sand.
• Nymphs are about the size of a poppy seed.
• Adult ticks are roughly the size of an apple seed when unfed, about 3 to 5 mm, but engorged females can grow up to 10 mm or half an inch

Thus, ticks start very small and can expand significantly in size after feeding on blood.