Twitter Bootstrap: div in container with 100% height

Set the class .fill to height: 100%

.fill { 
    min-height: 100%;
    height: 100%;
}

JSFiddle

(I put a red background for #map so you can see it takes up 100% height)

It is very simple. You can use

.fill .map 
{
  min-height: 100vh;
}

You can change height according to your requirement.

you need to add padding-top to "fill" element, plus add box-sizing:border-box - sample here bootply

Update 2019

In Bootstrap 4, flexbox can be used to get a full height layout that fills the remaining space.

First of all, the container (parent) needs to be full height:

Option 1_ Add a class for min-height: 100%;. Remember that min-height will only work if the parent has a defined height:

html, body {
  height: 100%;
}

.min-100 {
    min-height: 100%;
}

https://codeply.com/go/dTaVyMah1U

Option 2_ Use vh units:

.vh-100 {
    min-height: 100vh;
}

https://codeply.com/go/kMahVdZyGj

Also of Bootstrap 4.1, the vh-100 and min-vh-100 classes are included in Bootstrap so there is no need to for the extra CSS

Then, use flexbox direction column d-flex flex-column on the container, and flex-grow-1 on any child divs (ie: row) that you want to fill the remaining height.

Also see:
Bootstrap 4 Navbar and content fill height flexbox
Bootstrap - Fill fluid container between header and footer
How to make the row stretch remaining height