Floyd gets billed at 5'7.5 or 5'8. Canelo gets billed at 5'7 or 5'9. Seeing the two of them together they are the same height, or maybe Mayweather slightly taller. Remember: there are no official height measuring protocols like there are for weight. Listed heights are often/usually bumped up by an inch or two. Tyson claims 5'10 yet used to get listed at 5'11.5. Wladamir Klitschko gets billed at 6'6, yet I think I've heard him say 6'5 a few times in interviews. Truth be told: Mayweather: 5'7, or slightly over Alvarez: 5'7 Pacquiao: 5'5.5
Marisol Dominguez is 1.74 m (~5'8") and she looks a bit taller: http://www.tvnotas.com.mx/advf/imagenes/4d2b9decddc1c_350x0.jpg