By default, opencart has only two prefixes for option weights.
When the admin chooses an option for the product, he must specify its weight with a positive and negative prefix for the customer.
This can be very difficult on some products and we may even have to use a calculator.
This module adds six new items to this section so you can easily set the weight of options, these include math symbols or a combination of them:

%
% -
% +
=
*

See the use of these symbols in the example below, you can also test them in the demo version.

Demo:
Admin-panel: Product Edit
Shop: Product Page

Suppose you have a product with the following weight:

Main product weight = 100 g

With this plugin you can specify the weight of the options of this product as follows:

Weight of the first option: (60%) Final weight = 60 grams

Weight of the second option: (-10%) Final weight = 90 grams

Weight of the third option: (+ 10%) Final weight = 110 grams

Weight of the fourth option: (= 120) Final weight = 120 grams [Full weight]

Weight of the fifth option: (* 2) Final weight = 200 grams

Weight of the sixth option: (/ 2) Final weight = 50 grams

In addition to being functional, this plugin is also very small and simple.



See also "More Option Price Prefixes"

Extension Installation Guide
Upload the zip file via extensions / Installer / Upload
Once the upload is done, Please go to Extensions / Modifications and hit the refresh button. If the theme caches is enabled, Refresh the theme caches in the admin panel / Dashboard / Gear icon.

For install and support free click on the "GET SUPPORT" button on this page. or drop me an email: hoseynsabeti9@gmail.com