Respected sir! i'm 19 years old and 5'4" tall. is this average height? what should be my height at this age? i look smaller before my friends.

Genetically determin: The "average" height of the population depends on many factors, mostly out of ur control. For u, there is no "expected" height, & it isn't a contest to be taller. Many ppl share ur height in the world. Depending on ur parent's height, ur growth trajectory (as a child) & other conditions, 5'4" may be ur expected height. U may grow a few more inches, but not much more given ur age. Get used to 5'4"

Depends on genetic: factors. Generally your expected height may be determined based on your parents' heights. This is assuming they were in good health. Another factor is age at onset of puberty and growth pattern. Some boys have delayed growth and maturation so grow quite a lot after age 19. This is often inherited so the father may also have had late growth and puberty. Your doctor can do a bone age test.