WooCommerce - Get a shipping estimate for a product

functions.php

<?php
/**
 * Get a shipping estimate for a product
 *
 * @param \WC_Product|int|null $product
 *
 * @return array|null
 */
function get_product_shipping_estimate($product = null) {
    if ($product === null) {
        $product = $GLOBALS['product'];
    } elseif (is_int($product)) {
        $product = wc_get_product($product);
    }

    if (!$product->exists() || !$product->needs_shipping() || get_option('woocommerce_calc_shipping') === 'no') {
        return null;
    }

    /** @var \WC_Product[] $products */
    $products = [$product];
    if ($product->is_type('variable')) {
        /** @var \WC_Product_Variable $product */
        foreach ($product->get_children(true) as $id) {
            $products[] = $product->get_child($id);
        }
    }

    if (\WC()->customer->get_shipping_country()) {
        $destination = [
            'country' => \WC()->customer->get_shipping_country(),
            'state' => \WC()->customer->get_shipping_state(),
            'postcode' => \WC()->customer->get_shipping_postcode(),
            'city' => \WC()->customer->get_shipping_city(),
            'address' => \WC()->customer->get_shipping_address(),
            'address_2' => \WC()->customer->get_shipping_address_2(),
        ];
    } else {
        $destination = \wc_get_customer_default_location();
    }

    $package = [
        'destination' => $destination,
        'applied_coupons' => \WC()->cart->applied_coupons,
        'user' => ['ID' => \get_current_user_id()],
    ];

    $count = 0;
    $minimum = null;
    $maximum = null;
    $mean = 0;

    foreach ($products as $data) {
        $cartId = WC()->cart->generate_cart_id($data->id, $product->is_type('variable') ? $data->variation_id : 0);
        $price = $data->get_price_excluding_tax();
        $tax = $data->get_price_including_tax() - $price;

        $package['contents'] = [
            $cartId => [
                'product_id' => $data->id,
                'data' => $data,
                'quantity' => 1,
                'line_total' => $price,
                'line_tax' => $tax,
                'line_subtotal' => $price,
                'line_subtotal_tax' => $tax,
                'contents_cost' => $price,
            ]
        ];

        $packageRates = \WC_Shipping::instance()->calculate_shipping_for_package($package);
        /** @var \WC_Shipping_Rate $rate */
        foreach ($packageRates['rates'] as $rate) {
            if ($minimum === null || (float)$minimum->cost < (float)$rate->cost) {
                $minimum = $rate;
            }

            if ($maximum === null || (float)$maximum->cost > (float)$rate->cost) {
                $maximum = $rate;
            }

            $mean = (($mean * $count) + (float)$rate->cost) / ($count + 1);
            $count++;
        }
    }

    return compact('minimum', 'maximum', 'mean');
}