Div height can be made same as its width easily.
1 2 3 4 5 | div { width : 100px ; height : 0px ; padding-bottom : 100px ; } |
OR (Percentage will also work)
1 2 3 4 5 | div { width : 50% ; height : 0px ; padding-bottom : 50% ; } |
Works in all modern browsers.