2021 Update…
Bootstrap 5 (beta)
For aligning within a flexbox div or row…
ml-autois nowms-automr-autois nowme-auto
For text align or floats..
text-leftis nowtext-starttext-rightis nowtext-endfloat-leftis nowfloat-startfloat-rightis nowfloat-end
Bootstrap 4+
pull-rightis nowfloat-righttext-rightis the same as 3.x, and works for inline elements- both
float-*andtext-*are responsive for different alignment at different widths (ie:float-sm-right)
The flexbox utils (eg:justify-content-between) can also be used for alignment:
<div class="d-flex justify-content-between">
<div>
left
</div>
<div>
right
</div>
</div>
or, auto-margins (eg:ml-auto) in any flexbox container (row,navbar,card,d-flex,etc…)
<div class="d-flex">
<div>
left
</div>
<div class="ml-auto">
right
</div>
</div>
Bootstrap 4 Align Demo
Bootstrap 4 Right Align Examples(float, flexbox, text-right, etc…)
Bootstrap 3
Use the pull-right class..
<div class="container">
<div class="row">
<div class="col-md-6">Total cost</div>
<div class="col-md-6"><span class="pull-right">$42</span></div>
</div>
</div>
You can also use the text-right class like this:
<div class="row">
<div class="col-md-6">Total cost</div>
<div class="col-md-6 text-right">$42</div>
</div>