I thought 400px would work for 4.7 and 5 inch sizes, but it didn't worked. Content didn't fitted correctly. Suggest me the size for this so that I use the breakpoint. Otherwise I had make alternate layout for phones.
There isn't any fixed guideline on this and we don't create breakpoints as per the screen sizes, they are created wherer the site breaks as described here - Add breakpoints in Muse for mobiles and desktops.
Can you please share the link to your site so we can see what exactly going wrong and suggest you the solution?