A PowerShell function that displays a progress bar with ETA.

Display-Progress.ps1

<#
.Synopsis
	Displays a progress bar with ETA
.DESCRIPTION
	Long description
.EXAMPLE
	Example of how to use this cmdlet
	
	Display-Progress -Id 1 -Count $i -Total $total -Activity "Exporting $($item.TestType)"
#>
function Display-Progress
{
	[CmdletBinding()]
	Param
	(
		[int]$Id,
		[DateTime]$Start,
		[int]$Count,
		[int]$Total,
		[string]$Activity,
		[double]$PercentageSubItem
	)

	Begin
	{
	}
	Process
	{
		$prct = $Count / $Total
		$elapsed = (Get-Date) - $Start

		if ($PercentageSubItem) {
			$prct = (($Count - 1) / $Total) + ((1 / $Total ) * $PercentageSubItem)
		}

		$totalTime = ($elapsed.TotalSeconds) / $prct 
		$remain = $totalTime - $elapsed.TotalSeconds
		$eta = (Get-Date).AddSeconds($remain)

		$status = ("$($prct.ToString('P')) % ($Count/$total) {0:dd\.hh\:mm\:ss} eta $eta" -f (New-TimeSpan -seconds $remain))
		Write-Progress -Id $Id -Activity $Activity -Status $status -PercentComplete ($prct * 100)
	}
	End
	{
	}
}