BoBoiBoy's height is 145 cm in BoBoiBoy Galaxy. (At the age of 14)
His height is probably taller now in Movie 2 and Galaxy season 2. (as he is 15 in these)
I personally like to think his height is 5ft 5inch/165 cm (It's my height/I'm 16)
I'd be too weird to think that the boy I fangirl so hard on is a shortie. (so short than me in fact. It's funny when I imagine him in my room and doing all those cool moves when he is way shorter than my younger sister. (she's 13 lol)
I keep his and Fang's height the same in my fanfictions. (the above mentioned height) But in real you all know that Fang is a tab bit taller than BoBoiBoy. (probably 2-3 cm)