Margin utilities are the easiest way to add some structure to forms. They provide basic grouping of labels, controls, optional form text, and form validation messaging. We recommend sticking to margin-bottom utilities, and using a single direction throughout the form for consistency.

Feel free to build your forms however you like, with <fieldset>s, <div>s, or nearly any other element.

More complex forms can be built using our grid classes. Use these for form layouts that require multiple columns, varied widths, and additional alignment options.Requires the $enable-grid-classes Sass variable to be enabled (on by default).

By addinggutter modifier classes, you can have control over the gutter width in as well the inline as block direction.Also requires the $enable-grid-classes Sass variable to be enabled (on by default).

More complex layouts can also be created with the grid system.

Create horizontal forms with the grid by adding the .row class to form groups and using the .col-*-* classes to specify the width of your labels and controls. Be sure to add .col-form-label to your <label>s as well so they’re vertically centered with their associated form controls.

At times, you maybe need to use margin or padding utilities to create that perfect alignment you need. For example, we’ve removed the padding-top on our stacked radio inputs label to better align the text baseline.

Be sure to use .col-form-label-sm or .col-form-label-lg to your <label>s or <legend>s to correctly follow the size of .form-control-lg and .form-control-sm.

As shown in the previous examples, our grid system allows you to place any number of .cols within a .row. They’ll split the available width equally between them. You may also pick a subset of your columns to take up more or less space, while the remaining .cols equally split the rest, with specific column classes like .col-sm-7.

The example below uses a flexbox utility to vertically center the contents and changes .col to .col-auto so that your columns only take up as much space as needed. Put another way, the column sizes itself based on the contents.

You can then remix that once again with size-specific column classes.

Use the .col-auto class to create horizontal layouts. By addinggutter modifier classes, we’ll have gutters in horizontal and vertical directions. The .align-items-center aligns the form elements to the middle, making the .form-checkbox align properly.