Is there a way to track the amount of Bitcoins lost?

[squatz1]

This is something I've always wanted to know, as I know the max amount of Bitcoins in circulation is obviously not going to be the true number, as there are going to be people who lose their wallet access by some means and then are never able to get this BTC back. Is there a way to be able to track this sort of thing? Maybe through an estimate of the number of wallets that haven't been used for x amount of time.

I don't know if something like this already exists though if so do steer me in the right direction here.

[DevelopmentBank]

There is no exact science to determine if a certain bitcoins are lost or not. For all we know what we think is lost bitcoin could just be an inactive address where the owner is waiting for the right price to sell.

However, you can get estimates of how much total bitcoins have been lost from pure speculation.
Here is a thread that talks about it: https://bitcointalk.org/index.php?topic=2466779.0;all
Here is an article that talks about it in more detail: http://fortune.com/2017/11/25/lost-bitcoins/