function woocommerce_item_stock_on_archive() {
global $product;
if ( $product->get_stock_quantity() ) {
echo '<span class="sklad">Всего ' . $product->get_stock_quantity() . ' товаров</span>';
}
}
add_action( 'woocommerce_after_shop_loop_item', 'woocommerce_item_stock_on_archive');