It will depend what you want them for. Im 5'11 and 180 and if I was getting them as an all mtn ski, then I would go 188. This is the size I tried last season and they were fine all over. The 178 would feel short for an all mnt ski but be good in the park. So decide what you want them for and choose a length to suit. But for most 5'10 and above I would think the 188 would be the best size unless the ski is being used as a park ski.