How to add Thousands separators to a number with Powershell

When working with long numbers, they are much easier to read with the thousand separators included. The Powershell format operator makes it simple.

$Number = 2109999.86
'{0:N0}' -f $Number
'{0:N2}' -f $Number

Produces the following output:

As you can see from the above, the first example produces a whole number with no decimal places, and the second one includes two decimal places.

In practice, when I needed to do this, the number provided to me was actually a string read from a CSV File, so although you can use the format operator, it won’t do anything:

The string needs to be cast as a number before you can use the format operator in this way:

$StringNumber = "10456.21" 
$($StringNumber -as [decimal]).ToString('N2')

Produces a number with separators:

You can use the format operator for all sorts of things. You might like this post on how to format leading zeros with the format operator.