Quantity and weight changes simultaneously

[ahmedrazashaikh]

i want to achieve a functionality in shopify.
on product detail page there will be 2 fields to increase and decrease. One for quantity and other for weight. both the fields work simultanuously like if we increase quantity by 2 weight will be multiplied by 2 and price will be updated. I have attached the example of what i want actually. Here is the website where this functionality is applied. https://floorscenter.com/collections/browse-our-items/products/emser-cabo-13-x-13-ceramic-matte-tile

How can i achieve this in shopify.
Thanks in advance

[Jivan_Suhagiya]

Hi @ahmedrazashaikh 
It will require to do with javascript. You need to trigger change event apply logic to calculate another field