<style> body { overflow: hidden } div { width: 10px; height: 10px; background-color: #d64203; } </style> <body> <div id="a"></div> <div id="b"></div> <div id="c"></div> <div id="d"></div> <!-- Deliberately make the scrollbars appear to ensure that with 'overflow: auto' viewport units are calculated as if the scrollbars are _not_ there. --> <div style="width: 500px; height: 500px; background-color: black"> </body> <script> // client{Width, Height} consist of the area _inside_ the scrollbars, so we need // to calculate these units with 'overflow: hidden' set to ensure that there are // no scrollbars. This reflects the fact that with 'overflow: auto' set, viewport // units are sized without taking the scrollbars into account. var vw = 0.01 * document.body.clientWidth; var vh = 0.01 * document.body.clientHeight; var vmin = Math.min(vw, vh); var vmax = Math.max(vw, vh); document.body.style.overflow = "auto"; document.getElementById('a').style.width = (50 * vw) + "px"; document.getElementById('b').style.height = (25 * vh) + "px"; document.getElementById('c').style.width = (35 * vmin) + "px"; document.getElementById('d').style.height = (25 * vmax) + "px"; </script>