How to Find Out How Much RAM Your Mac Has

by Michael Cox

When your Mac slows to a crawl, the problem may not be an outdated processor or Internet voodoo -- it may be your RAM. It's important to know where you stand on memory, both how much you've got and how your applications are using it, to keep your computing as speedy and trouble-free as possible. If your applications are RAM-hungry, adding more memory may improve their performance significantly, at a fraction of the cost of a new computer.

Installed RAM

Choose "About This Mac" from the Apple menu. The "About This Mac" window displays the total amount and type of RAM you have installed.

Click "More Info" to open the System Profiler. Under "Hardware" in the left-hand pane, click "Memory." The upper right-hand pane displays what's installed in each of your Mac's memory slots, including the size, type, speed and status of each module.

Compare the amount of installed RAM on your computer with the amount your Mac is capable of using. You can find this information on Apple's Technical Specifications page for your specific model.


Open the Activity Monitor tool located in your Mac's Utilities folder, within the Applications folder.

Click "System Memory" on the button bar. Immediately below the button bar, information on your RAM usage appears. The pie chart to the right represents your total installed RAM and should match the amount you see in the "About This Mac" window. The amounts making up this total appear to the left of the pie chart. For definitions of each category visit the Apple Web page "Using Activity Monitor" (see link in References).

View individual applications' memory usage, as well as that of operating system processes, in the list above the button bar. Sort the list by clicking "Real Mem" to see your open applications and system processes ordered by they memory they use.


  • To quickly determine whether you could benefit from adding RAM to your Mac, view the "Page Outs" number in the Activity Monitor. This number represents the amount of information your Mac must move from RAM to your hard disk. According to Apple, if the number in parentheses is above zero as you work normally, adding RAM may improve your computer's performance.
  • Most Macs offer user-accessible RAM slots for easy upgrades. To determine how to install RAM modules in your Mac, see its user guide.


  • Using Activity Monitor's "Stop Process" feature may result in system instability or crashing. A more system-friendly way to stop an application from running is to right-click its icon in the Dock and choose "Quit" or "Force Quit."


About the Author

Michael Cox writes about lifestyle issues, popular culture, sports and technology. In a career spanning more than 10 years, he has contributed to dozens of magazines, books and websites, including and "Adobe Magazine." Cox holds a professional certificate in technical communications from the University of Washington.

Photo Credits

  • Brian Kersey/Getty Images News/Getty Images