How to make an element width: 100% minus padding?

Question

I have an html input.

The input has padding: 5px 10px; I want it to be 100% of the parent div\'s width(which is fluid).

However using widt

Answer 1

This is why we have box-sizing in CSS.

I’ve edited your example, and now it works in Safari, Chrome, Firefox, and Opera. Check it out: http://jsfiddle.net/mathias/Bupr3/ All I added was this:

input {
  -webkit-box-sizing: border-box;
     -moz-box-sizing: border-box;
          box-sizing: border-box;
}

Unfortunately older browsers such as IE7 do not support this. If you’re looking for a solution that works in old IEs, check out the other answers.

Answer 2

Here is the recommendation from codeontrack.com, which has good solution examples:

Instead of setting the width of the div to 100%, set it to auto, and be sure, that the <div> is set to display: block (default for <div>).

Answer 3

Move the input box' padding to a wrapper element.

<style>
div.outer{ background: red; padding: 10px; }
div.inner { border: 1px solid #888; padding: 5px 10px; background: white; }
input { width: 100%; border: none }
</style>

<div class="outer">
    <div class="inner">
       <input/>
    </div>
</div>

See example here: http://jsfiddle.net/L7wYD/1/

Answer 4

Try this:

width: 100%;
box-sizing: border-box;

Answer 5

You can do it without using box-sizing and not clear solutions like width~=99%.

Demo on jsFiddle:

• Keep input's padding and border
• Add to input negative horizontal margin = border-width + horizontal padding
• Add to input's wrapper horizontal padding equal to margin from previous step

HTML markup:

<div class="input_wrap">
    <input type="text" />
</div>

CSS:

div {
    padding: 6px 10px; /* equal to negative input's margin for mimic normal `div` box-sizing */
}

input {
    width: 100%; /* force to expand to container's width */ 
    padding: 5px 10px;
    border: none;
    margin: 0 -10px; /* negative margin = border-width + horizontal padding */ 
}

Answer 6

Assuming i'm in a container with 15px padding, this is what i always use for the inner part:

width:auto;
right:15px;
left:15px;

That will stretch the inner part to whatever width it should be less the 15px either side.