The CSS width, height, min-width, min-height, max-width, and max-height properties are used to set the size (including minimum/maximum) of an element.

  • width – sets the width of the element
  • height – sets the height of the element
  • min-width – sets the smallest width the element can have
  • min-height – sets the smallest height the element can have
  • max-width – sets the largest width the element can have
  • max-height – sets the largest height the element can have

This element (box) is 100% wide x 80px high

Setting the Size

This is the size that the element will appear on all screens.

					div {
    width: 100%;
    height: 80px;

Normally, you would only set one or the other (width or height) and not both (although you may set the height to auto, especially with an image element). You would let the content dictate the height of the element. For example, this green note has a set % width, but the height remains unset and will grow to accommodate the text.

					img {
    width: 100%;
    height: auto;

Setting the Minimum and Maximum Size

This is the smallest and largest that an element is to appear on the screen. For instance, if someone is using a very large screen and you simply have the width set to 100%, the content of the element will stretch entirely across the screen, which could look awkward, and be difficult to read. So you set a max-width to something where it will grow with the screen size, but only to a certain point.

Similarly, you may want to set a minimum size for times when having the element smaller would look awkward or perhaps unreadable.

					div {
    max-width: 1440px;
    min-width: 325px;

Setting the min-width and max-width and letting the height grow as needed to accommodate the contents is often used. That is why we aren’t setting the min/max for the height in the example above.

Width and Height Properties