Calculating distance between 2 post codes

[GypsyBoy]

I’m new to php and MySQL, and i'm just getting my feet dirty...

Basically i am working on a message board, i need to be able to post a thread like you would do normally and also ask for post code, to be stored with the thread.

Then I want to modify search.php and create a field where you type post code of your liking and have it compared WITH thread post code and then calculate the distance  between  post code in a thread and   post code you type into search

Does that make sense? 

How do I go about that?.

Here’s a good one:

http://www.geopostcode.org.uk/findmynearest.php

Any thing else? Oh and I need a UK version of this (for now) as you probably guessed!

 

Edited April 9, 2018 by GypsyBoy

[justsomeguy]

In general, you need a database listing the approximate center of each area using lat/long, and then you just use one of the existing algorithms to find the difference between 2 coordinates.  It's not going to be exact obviously, because you're only finding the distance between the approximate centers of each area, but that's how they do it.