Javascript shipping calculator

Avg Bid (USD)
Project Budget (USD)
$30 - $250

Project Description:
I need a shipping calculator for a website. The customer will enter a postcode to see the shipping cost.
The calculation is: $20 + (weight x $rate) x1.2 x1.1 = Total shipping.
The $rate value changes for each shipping region and there is about 45 regions and each region has several post code ranges.
The weight will be a constant value, for example 20kg.

I can supply the post code, region and rate data in any format you want.

I just need the basic javascript code for it. I will modify and update the website myself.

Skills required:
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