How to calculate Time Left (remaining time) using percentage

Hey guys i'm having problems creating a result that displays me the estimated time left until my script is completed

the basics :
It's a simple script with a for from 1 to N rows
I've made a percent calculator in order to see where I am.

in order to the the code about how long it will take to finish i'm using the following code :

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Estimates between different PC finish time : 130 seconds and 180 seconds.

My purpose is to display using the

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The estimated time left should be calculated on the speed of the percentage ?

Something like WinRAR?

Thank you

CK76, i've noticed that estimate won't be anywhere near accurate as winrar

As for the rest, i dont know how to add or what to add as a formula to have the expected result

So let's say you have loop.

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You will need something like below.

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perfect ! thanks !