Form factors for storage media

The following table lists various hard disk and SSID form factors and gives their actual size in millimetres.


Factor Profile Platter Size (mm) Width (mm) Depth (mm) Height (mm) Comment
5.25″ Full-Height 130.05 146.05 203.2 82.55 All drives in early 1980s; Large capacity drives with many platters as late as the mid-1990s
5.25″ Half-Height 130.05 146.05 203.2 41.4 Early 1980s through early 1990s
5.25″ Low-Profile 130.05 146.05 203.2 25.4 Quantum Bigfoot, mid-to-late 1990s
5.25″ Ultra-Low-Profile 130.05 146.05 203.2 19.05 Quantum Bigfoot, mid-to-late 1990s
5.25″ Ultra-Low-Profile 130.05 146.05 203.2 20.32 Quantum Bigfoot, mid-to-late 1990s
3.5″ Half-Height 63.5 101.6 146.05 41.4 High-end, high-capacity drives
3.5″ Half-Height 76.2 101.6 146.05 41.4 High-end, high-capacity drives
3.5″ Half-Height 95 101.6 146.05 41.4 High-end, high-capacity drives
3.5″ Low-Profile 63.5 101.6 146.05 25.4 Industry standard, most common form factor for PC hard disks
3.5″ Low-Profile 76.2 101.6 146.05 25.4 Industry standard, most common form factor for PC hard disks
3.5″ Low-Profile 95 101.6 146.05 25.4 Industry standard, most common form factor for PC hard disks
2.5″ 19 mm Height 63.5 69.85 100.08 19.05 Highest-capacity 2.5″ drives, used in full-featured laptop systems
2.5″ 17 mm Height 63.5 69.85 100.08 17.02 Mid-range capacity drives used in some laptop systems
2.5″ 12.5 mm Height 63.5 69.85 100.08 12.45 Low-capacity drives used in small laptops (subnotebooks)
2.5″ 9.5 mm Height 63.5 69.85 100.08 9.4 Lowest-capacity drives used in very small laptops (mini-subnotebooks)
PC Card Type I 45.72 54.1 85.6 3.3 Not used for hard disks
PC Card Type II 45.72 54.1 85.6 5.08 Smaller-capacity expansion hard disks for laptops and consumer electronics
PC Card Type III 45.72 54.1 85.6 10.41 Higher-capacity expansion hard disks for laptops
Compact Type I 25.4 42.93 36.07 3.3 Smaller-capacity flash cards for digital cameras, hand-held computers and consumer electronics; not used for  hard disks (yet)
Compact Type II 25.4 42.93 36.07 5.08 Larger-capacity flash cards and hard disks for digital cameras, hand-held computers and consumer electronics
SD
(Secure data)
  n/a 32 24 2.1 Digital cameras, MP3 players and many other devices. Available in a variety of capacites:-

Standard SD: 4 MB to 4 GB
SDHC: 4 GB to 32 GB
SDXC: 32 GB to 2 TB