Bootstrap includes a responsive, mobile first fluid grid system that appropriately scales up to 12 columns as the device or viewport size increases. It includes predefined classes for easy layout options, as well as powerful mixins for generating more semantic layouts.

### Grid options

See how aspects of the Bootstrap grid system work across multiple devices with a handy table.

| Extra small devices Phones (<768px) | Small devices Tablets (≥768px) | Medium devices Desktops (≥992px) | Large devices Desktops (≥1200px)
--- | --- | --- | --- | ---
Grid behavior | Horizontal at all times | Collapsed to start, horizontal above breakpoints
Container width | None (auto) | 750px | 970px | 1170px
Class prefix | `.col-xs-` | `.col-sm-` | `.col-md-` | `.col-lg-`
# of columns | 12
Column width | Auto | 60px | 78px | 95px
Gutter width | 30px (15px on each side of a column)
Nestable | Yes
Offsets | Yes
Column ordering | Yes

### Example: Stacked-to-horizontal

Using a single set of `.col-md-*` grid classes, you can create a basic grid system that starts out stacked on mobile devices and tablet devices (the extra small to small range) before becoming horizontal on desktop (medium) devices. Place grid columns in any `.row`.

.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-1
.col-md-8
.col-md-4
.col-md-4
.col-md-4
.col-md-4
.col-md-6
.col-md-6

### Example: Mobile and desktop

Don't want your columns to simply stack in smaller devices? Use the extra small and medium device grid classes by adding `.col-xs-*` `.col-md-*` to your columns. See the example below for a better idea of how it all works.

.col-xs-12 .col-md-8
.col-xs-6 .col-md-4
.col-xs-6 .col-md-4
.col-xs-6 .col-md-4
.col-xs-6 .col-md-4
.col-xs-6
.col-xs-6

### Example: Mobile, tablet, desktops

Build on the previous example by creating even more dynamic and powerful layouts with tablet `.col-sm-*` classes.

.col-xs-12 .col-sm-6 .col-md-8
.col-xs-6 .col-md-4
.col-xs-6 .col-sm-4
.col-xs-6 .col-sm-4
.col-xs-6 .col-sm-4

### Offsetting columns

Move columns to the right using `.col-md-offset-*` classes. These classes increase the left margin of a column by `*` columns. For example, `.col-md-offset-4` moves `.col-md-4` over four columns.

.col-md-4
.col-md-4 .col-md-offset-4
.col-md-3 .col-md-offset-3
.col-md-3 .col-md-offset-3
.col-md-3 .col-md-offset-2
.col-md-6 .col-md-offset-1

### Nesting columns

To nest your content with the default grid, add a new `.row` and set of `.col-md-*` columns within an existing `.col-md-*` column. Nested rows should include a set of columns that add up to 12 or less.

Level 1: .col-md-9
Level 2: .col-md-6
Level 2: .col-md-6

### Column ordering

Easily change the order of our built-in grid columns with `.col-md-push-*` and `.col-md-pull-*` modifier classes.

.col-md-9 .col-md-push-3
.col-md-3 .col-md-pull-9