Let's find out by giving the boxes a border!

<html>
 <head>
  <style>.box {background-color: gray;width: 50px;height: 25px;border: 1px solid black;display: inline;}</style>
 </head>
 <body><div class="box"></div><div class="box"></div></body>
</html>
]]>

As it turns out, inline elements don't have widths and heights. Therefore, they take up exactly as much space as their content needs.

Don't the values look like we need a shorthand property?