What Size USB Flash Drive Do I Need?

The size, speed and security needs of a USB flash drive depend on usage

USB drive
JGI/Jamie Grill/Getty Images
Was this page helpful?

The size of USB flash drive you need depends on what you are planning to do with it. If you know you'll only be using the thumb drive to move Word documents from computer to computer, stick with a 2GB or 4GB USB flash drive and you'll be fine. If you're planning on archiving your entire photo or music library, you may need a 256GB or larger flash drive. If you're moving or archiving video, buy the biggest flash drive you can find.

USB Flash Drive Considerations

The capacities of USB flash drives range from 2 gigabytes to 1 terabyte. Although the drives are affordable options for expanding storage capabilities, the price increases with the size. When you are shopping for a flash drive, you'll also be interested in transfers speed—whether the USB flash drive is USB 2.0 or 3.0—and security.

Estimating Storage Space Needs

There's no simple formula for estimating your storage needs. The number of photos or songs that fits on a USB flash drive varies widely because of the type of media you use and the size and quality of each file. For example, if each of your photos is 6 megapixels in size, you can fit 1,000 on a 2GB drive, 8,000 on a 16GB drive and 128,000 on a 256GB drive. However as the size increases, the number of photos that fit decreases. If you work with high-resolution photos that average 24MP, you'll only be able to put 250 on the small 2GB flash drive and 32,000 on the 256GB drive.

The same problem exists when trying to estimate the size of music and video, which also vary in quality. If you place all the files you want to transfer to a USB flash drive in one folder, you can get the size of the folder and that tells you how much space you need to move that one folder. If you shoot HD video, don't bother with any drive at the small end of the size scale.

A 16GB flash drive holds only one minute of HD video, while a 256GB drive holds just 224 minutes.

In contrast, Word documents and Excel spreadsheets take up little space. If you are a student transferring these types of files between computers, a 2GB drive is all you need. 

The Difference Between USB 2.0 and USB 3.0

Whether you choose a USB 2.0 or USB 3.0 depends in part on the device you are transferring from and the port you use. Confirm which speed your computer or other device supports before buying a USB drive. If your equipment supports USB 3.0, buy that speed drive. Its transfer rate is 10 times faster than the speed of a USB 2.0 drive. 

About Security

Depending on your usage, you may want to buy a secure USB flash drive. This may not be necessary if you are just transferring a few files from one home computer to another, but if you are using the drive with many computers or are archiving important or proprietary data on the drives, security becomes a concern. The security issues with USB thumb drives include:

  • Their small size may cause them to be lost or overlooked.
  • They are hard to track physically. Some companies ban their use for this reason.
  • They can transfer malware from one computer to another and have done so frequently.

    Nothing can be done about the small size of the thumb drive without forfeiting its portability, but software encryption—on Windows and Mac computers and from security companies—and hardware encryption on the USB drives themselves are available to prevent malware transfer and unauthorized access.