Hello Employer,
I have gone through your project description,
I am working as a web developer since last 5.5 years. and I am working in Wordpress / Magento / OpenCart / joomla and other PHP platforms as well.
We have make the module for calculator , and you have to put the values of area wise shipping,
So it will take time, If you allow me, then we can discuss further,
Hope to speak soon
Thank you