I'm selling rolls that come in two widths. The user can choose which width is required however the user can also type in the length in metres. Then a price is calculated.
For instance if the price is £5 square metre, and the user chooses the 4m option and types in a length of 4.5m then the total cost should be 5 x 4 x 4.5
Is there an existing extension, is this simple to program ?
There is not such extension that meets your requirements, however you try price caculator extension to set price per unit,. The unit can be meter, inch, centimeter, etc. Once user input the desired measurement in length and width this extension automatically calculate price.
This extension can be made useful with minor changings, you can either do iut by your self as extension is OpenSource or contact the FmeExtensions to customize it for you.
You can have a look at this Magento 2 Price Formula extension – https://www.itoris.com/magento-2-product-price-formula.html
The plugin allows to create math formulas and conditions based on the product options selected. Your final price will depend on the entered data.
You can also refer to this article to know more about how to calculate the final price based on the product dimensions – https://www.itoris.com/blog/magento-2-extensions/price-dependent-on-custom-products-size-in-magento-...
The Price Formula extension is also available for Magento 1 – https://www.itoris.com/magento-product-price-formula.html
Hope it will be of help!