Here’s another little WooCommerce tweak for your website user experience: let’s add some text in front of the Add to Cart button that says “Quantity: “.
As usual, we go looking for the right “hook”… the WooCommerce plugin is full of them and adding some custom content in the exact position we want is very easy. Enjoy!

PHP Snippet: Add “Quantity” Label in front of Add to Cart Button – WooCommerce
/**
* @snippet Add "Quantity:" before Add to Cart Button - WooCommerce
* @how-to Get CustomizeWoo.com FREE
* @author Rodolfo Melogli
* @testedwith WooCommerce 8
* @donate $9 https://businessbloomer.com/bloomer-armada/
*/
add_action( 'woocommerce_before_add_to_cart_quantity', 'bbloomer_echo_qty_front_add_cart' );
function bbloomer_echo_qty_front_add_cart() {
global $product;
if ( $product->get_min_purchase_quantity() == $product->get_max_purchase_quantity() ) return;
echo '<div class="qty">Quantity: </div>';
}
And a couple of CSS lines as well:
div.qty {
float: left;
padding: 10px;
}