1. Open up vSphere Web Client.
2. Log in to your vCenter Server.
3. On the Home screen, select VMs and Templates.
4. Click on the VM where you want to monitor Utilization of Memory.

5. Go to the Summary tab and locate Memory Usage in the summary at the top and Memory Active in the VM Hardware tile:

You can see in the preceding example that the Consumed Host Memory of the VM is 16384 MB and its Active Guest Memory is 14581 MB.

You can also check this through the performance graph of the VM. Here is what you need to do to get to this:

1. Open up vSphere Web Client.
2. Log in to your vCenter Server.
3. On the Home screen, select VMs and Templates.
4. Choose the VM where you want to monitor Utilization of Memory.
5. Go to the Monitor tab, then the Performance tab.
6. Select Memory from the drop-down list.
7. Click on Chart Options.

8. Make sure that the Active and Consumed counters are selected and click on OK to see the result:

You can see in this example that the memory usage of this VM is 89 percent. Guest Active Memory and Consumed Host Memory are also quite high.

Now to check the host memory, follow these steps:

1. Open up vSphere Web Client.
2. Log in to your vCenter Server.
3. On the Home screen, select Hosts and Clusters.
4. Choose the ESXi host where you want to monitor Utilization of Memory.
5. Go to the Summary tab.

6. On the top-right corner, you will see Host Memory Usage:
   
7. Now go to the Configure tab, then on the left scroll down to the Hardware section, and then click on Memory to see VM memory usage: