Bootstrap CSS class .col-form-label-lg

    <div class="row">
        <label for="colFormLabelExample" class="col-sm-2 col-form-label-lg">Email</label>
        <div class="col-sm-10">
            <input type="email" class="form-control form-control-lg" id="colFormLabelExample" placeholder="Enter your e-mail">
        </div>
    </div>