Check your computer's manufacture date in system settings

The fastest way to find your computer's age is to look at the system information built into Windows or macOS. This tells you when the operating system was installed, which is usually close to when you bought the machine — though not always, especially if you upgraded the OS later or bought a used computer.

On Windows 10 or 11, right-click the Start button, select "System," and scroll down to "System info." Look for "Original Install Date" if it appears, or note the "OS Build" number and date. If that field is blank, open Settings, go to System > About, and check "Installation date" near the bottom of the page.

On macOS, click the Apple menu, select "About This Mac," and look at the "System Report" button. In the window that opens, find "System Firmware Version" or check the "Hardware Overview" tab for any date stamps. The "Build Version" number can also be cross-referenced online to narrow down the year.

Key Takeaways

  • Windows and macOS both store an installation date in system settings, though this shows when the operating system was installed, not necessarily when you bought the computer.
  • The serial number on your computer's case or battery can be looked up on the manufacturer's website to find the exact manufacture date.
  • If you bought the computer used or upgraded the operating system, the system date may not match the actual age of the hardware.
  • BIOS or firmware version numbers can be cross-referenced online to estimate when the computer was built.

Look up the serial number on the manufacturer's website

The most reliable way to find your computer's true age is to use the serial number, which the manufacturer records with a build date. This works even if you upgraded the operating system or bought the machine used.

Find the serial number on a sticker on the bottom or back of your laptop, or inside the battery compartment on older models. On desktop computers, it is usually on the back panel or inside the case. Write down the full serial number exactly as it appears.

Go to the support or warranty page of your computer's manufacturer — Dell, HP, Lenovo, Apple, Asus, or whoever made it — and look for a "Check Warranty" or "Product Information" tool. Enter your serial number, and the site will return the manufacture date and original warranty period. This date is the most accurate measure of how old your computer actually is.

Check the BIOS or firmware version for a build date

Your computer's BIOS (Basic Input/Output System) or firmware contains a version number that often includes a date code. This is less straightforward than the serial number but works if the sticker has worn off or you cannot access the manufacturer's lookup tool.

On Windows, open Settings > System > About and look for "BIOS Version/Date" or "System Firmware Version." The date listed here is when the BIOS was last updated, which is usually close to the manufacture date but not always exact.

On macOS, go to Apple menu > About This Mac > System Report, then click "Hardware" in the sidebar. Look for "Boot ROM Version" or "System Firmware Version." You can search this version number online along with your computer model to find the approximate build date.

Examine the physical condition and component dates

If digital records are not available, the physical hardware itself can give clues. Look inside the computer (if you are comfortable opening it) for date codes printed on the hard drive, RAM sticks, or motherboard. These are usually in a format like "2019-03" or "19W" (meaning week 19 of 2019).

The hard drive or solid-state drive often has a manufacture date on its label. If you see multiple dates on different components, the most recent one is usually closest to when the computer was assembled.

Battery condition is also a clue: lithium batteries degrade predictably over time. If your laptop battery holds a charge for only an hour or two and the system date shows the OS was installed five years ago, the computer is likely at least that old.

Ask the seller or previous owner if you bought used

If you purchased the computer secondhand, the person who sold it to you may have the original receipt or documentation showing the purchase date. This is not the same as the manufacture date, but it gives you a starting point.

Many used computer sellers list the approximate age in their product description. If you bought from a refurbished retailer, they often include a report showing when the device was tested and prepared for resale, which is more recent than the manufacture date but still useful context.

If you have no contact with the seller, the serial number lookup remains your best option, since it will show you the actual manufacture date regardless of how many owners the computer has had.

Understand why the dates might not match

The system installation date and the manufacture date are often different. A computer built in March 2019 might not have Windows installed until June 2019 if it sat in a warehouse or store. If you upgraded from Windows 10 to Windows 11, the installation date will show only when you upgraded, not when you bought the machine.

Refurbished computers are another source of confusion: the system date might show a recent reinstall, but the serial number will reveal the original manufacture date. This does not make the computer older or less reliable — refurbished machines are tested and often come with the same warranty as new ones — but it explains why the dates do not line up.

If you are trying to determine whether your computer is still under warranty, use the manufacture date from the serial number lookup. If you are trying to decide whether to replace aging hardware, consider both the manufacture date and how the computer actually performs for your needs.

Frequently Asked Questions

What if the serial number sticker is worn off or missing?

Try the BIOS or firmware version lookup, which does not require the serial number. You can also open the computer case (if you are comfortable doing so) and look for date codes on internal components like the motherboard or hard drive. If none of these work, the system installation date is your only remaining option, though it may not be accurate.

Does the manufacture date tell me how long the computer will last?

Not directly. A five-year-old computer can run perfectly well if it has been maintained and not heavily used. Age matters less than how the machine performs for what you need it to do. Check the hard drive health, battery condition (on laptops), and whether the processor and RAM still meet your needs.

Can I find the age of a computer I do not own?

Only if you have the serial number and access to the manufacturer's lookup tool. If you are shopping for a used computer, ask the seller for the serial number before you buy, then verify the manufacture date yourself. This protects you from buying a computer that is older than advertised.

Why does my Mac show a build version instead of a date?

Apple uses build version numbers for macOS rather than straightforward dates. You can search the build number online (for example, "macOS Monterey 12.0.1 build number") to find the release date, which is close to when your Mac was manufactured if the OS has not been upgraded since purchase.

Is a refurbished computer older than a new one?

A refurbished computer has an older manufacture date but may have been recently tested, repaired, and had its operating system reinstalled. The manufacture date is older, but the actual condition and warranty are often comparable to a new computer. Check the warranty period and return policy before buying.