.wrapper { width: 960px; /* Some arbitrary bounding. 960px is usually the width of fixed-width layouts. */ } .three-column { width: 33%; /* 100%/3 = ~33% */ height: 200px; /* Stick in an arbitrary height for display purposes. */ float: left; background: #f00; /* Red, again for display purposes */ } .three-column:first-child { background: #0f0; /* Green, to show the column differences */ } .three-column:last-child { background: #00f; /* Blue, to show the column differences */ }