I am a magento 2 starter with much experience in magento 1. I can't find the relevant scripts which are used to calculate the price for configurable products.

I need a basic guide on how the configuration works please so that I can modify it.

E.g. I need to add a customise-able option with title Length and the price should change based on it's value.

So if the price is $1000 and 1000 millimetres is set then the price should be $1000,

if 500 millimetres is set, then the price should be 500$.

If 2000 millimetres is set then the price should be 2000$ and so on...

price = (price * (length / 1000))

Where do I have to add this logic?


Magento 2 config product price is different with Magento 1.

  • In Magento 1 the price is calculated based on super attributes.

  • In Magento 2 the price is taken from child product.

In your case, we have two methods:

  1. Using Magento Backend: Generate the children with option Apply unique prices by attribute to each SKU, enter fixed price to each value of length attribute.

  2. Using Magento source code: create a 3rd module and override getValue() function in /vendor/magento/module-catalog/Pricing/Price/BasePrice.php class using di.xml. The code should be:

    public function getValue()
        if ($this->value === null) {
            $this->value = false;
            foreach ($this->priceInfo->getPrices() as $price) {
                if ($price instanceof BasePriceProviderInterface && $price->getValue() !== false) {
                    $this->value = min($price->getValue(), $this->value ?: $price->getValue());
        $objectManager = \Magento\Framework\App\ObjectManager::getInstance();
        $product = $objectManager->create('Magento\Catalog\Model\Product')->load($this->product->getId());
        if ($product) {
            $length = $product->getResource()->getAttribute('length')->getFrontend()->getValue($product);
            if ($length) {
                $this->value = $this->value * ($length / 1000);
        return $this->value;

    Tested in Magento 2.3.0

That's it.

| improve this answer | |
  • But the length attribute ranges from 0 to 6000, so do I need to create 6000 values? I think it would be better to create a logic so that the price is multiplied by length / 1000. – Black Jul 8 '19 at 10:10
  • @Black So it's configurable product + length or simple product + length. So you will need to override the Core function in order to change the price. Let create an override module for this. – Jamy Jul 8 '19 at 10:22
  • And where are the relevant files? I also need to do this for the price display on the frontend, how does magento know which price to show in frontend? Does it work by javascript, is a request to a controller made? – Black Jul 8 '19 at 10:34
  • @Black If you only want to change the base price (excluding tax and option prices), let override this file /vendor/magento/module-catalog/Pricing/Price/BasePrice.php. Add this line at the end of getValue() function (before return): $this->value = $this->value * ($this->product->getLength / 1000)) – Jamy Jul 8 '19 at 10:38
  • ok, but note that not every configurable product will have a length. Does it also take care of the calculation in the frontend? – Black Jul 8 '19 at 10:41

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