Change total woocommerce order weight

Question

I need change total weight of order in woocommerce website.

For example: I have a 3 product in a cart: 1 - 30g; 2 - 35; 3 - 35g; total = 30+35+35 = 100g, but I want

Answer 1

Hook in the right filter action

Let's have a look on the function get_cart_contents_weight():

public function get_cart_contents_weight() {
    $weight = 0;

    foreach ( $this->get_cart() as $cart_item_key => $values ) {
        $weight += $values['data']->get_weight() * $values['quantity'];
    }

    return apply_filters( 'woocommerce_cart_contents_weight', $weight );
}

There is a filter hook we can use: woocommerce_cart_contents_weight

So we can add a function to this filter:

add_filter('woocommerce_cart_contents_weight', 'add_package_weight_to_cart_contents_weight');

function add_package_weight_to_cart_contents_weight( $weight ) {        
    $weight = $weight * 1.3; // add 30%     
    return $weight;     
}

---

To add the package weight to every product separately, you can try this:

add_filter('woocommerce_product_get_weight', 'add_package_to_product_get_weight');

function add_package_to_product_get_weight( $weight ) {
    return $weight * 1.3;
}

But do not use both solutions together.

Answer 2

It's working at my end. Update total weight to new weight value.

add_action('woocommerce_cart_collaterals', 'myprefix_cart_extra_info');
function myprefix_cart_extra_info() {
    global $woocommerce;
    echo '<div class="cart-extra-info">';
    echo '<p class="total-weight">' . __('Total Weight:', 'woocommerce');
    echo ($woocommerce->cart->cart_contents_weight*0.3)+$woocommerce->cart->cart_contents_weight;   
    echo '</p>';
    echo '</div>';
}