Getting output as infinite or Nan - powershell

Question

I have tried the below command to get the memory usage of the computer but getting error as infinite or NaN.
$Totalsizemem=gwmi Win32_PhysicalMemory | Measure-Object -Property capacity -Sum | Foreach {"
{0:N2}" -f ([math]::round(($_.Sum / 1GB),2))}
gwmi -computername localhost Win32_Process | Sort WorkingSetSize -Descending | Select
Name,#{n="Memoryusage(%)";Expression ={[math]::round(($_.WorkingSetSize / 1GB),1) /
$Totalsizemem*100}} | Select -First 10 | Format-Table -AutoSize | Out-Default
The expected output is -
Name Memoryusage(%)
---- --------------
powershell_ise.exe 0.655737704918033
explorer.exe 0.655737704918033
explorer.exe 0.655737704918033
explorer.exe 0.655737704918033
but the output i'm getting -
Name Memoryusage(%)
---- --------------
powershell_ise.exe ∞
svchost.exe ∞
explorer.exe NaN
svchost.exe NaN
explorer.exe NaN
Does anyone know how to rectify this?

Answer 1

You keep rounding and formatting the intermediate results, sacrificing accuracy to the point where your data is meaningless.
Keep it simple:
$Totalsizemem = Get-WmiObject Win32_PhysicalMemory | Measure-Object -Property Capacity -Sum |Select -Expand Sum
Get-WmiObject Win32_Process |Sort WorkingSetSize -Descending |Select Name,#{Name='MemoryUsage(%)';Expression={$_.WorkingSetSize * 100 / $Totalsizemem}} -First 10