Getting CPU usage % in .NET Core

In this article I will share a way of getting the CPU usage % of a .NET core app. This matches up with the value reported in task manager.

In full .NET framework, most people used thePerformanceCounter class to work this out like so:

private async Task<int> GetCpuUsageForProcess()
{
  var currentProcessName = Process.GetCurrentProcess().ProcessName;
  var cpuCounter = new PerformanceCounter("Process", "% Processor Time", currentProcessName);
  cpuCounter.NextValue();
  await Task.Delay(500);
  return (int)cpuCounter.NextValue();
}

The PerformanceCounter class isn’t available in .NET Core though so another approach has to be used.

This involves using the Process class from System.Diagnostics and the TotalProcessorTime property along with a delay in time. It is then possible to figure out how much processor time has been consumed from the process and hence get the percentage:

private async Task<double> GetCpuUsageForProcess()
{
    var startTime = DateTime.UtcNow;
    var startCpuUsage = Process.GetCurrentProcess().TotalProcessorTime;
    await Task.Delay(500);
    
    var endTime = DateTime.UtcNow;
    var endCpuUsage = Process.GetCurrentProcess().TotalProcessorTime;
    var cpuUsedMs = (endCpuUsage - startCpuUsage).TotalMilliseconds;
    var totalMsPassed = (endTime - startTime).TotalMilliseconds;
    var cpuUsageTotal = cpuUsedMs / (Environment.ProcessorCount * totalMsPassed);
    return cpuUsageTotal * 100;
}

An example of how this can be used can be found on my github at https://github.com/jackowild/CpuUsagePercentageDotNetCoreExample

It outputs the CPU usage % every 2 seconds: