Ethernet cable types
Ethernet cables are categorized by their bandwidth and construction. All standard categories use RJ-45 connectors and are backward compatible — a Cat6 cable works in a Cat5e port and vice versa, limited to the lower spec.
Category comparison
| Category | Max bandwidth | Max speed | Max length | Shielding |
|---|---|---|---|---|
| Cat5e | 100 MHz | 1 Gbps | 100 m | Unshielded (UTP) |
| Cat6 | 250 MHz | 10 Gbps up to 55 m; 1 Gbps to 100 m | 100 m | UTP or STP |
| Cat6A | 500 MHz | 10 Gbps | 100 m | STP (shielded required for 10G at 100 m) |
| Cat7 | 600 MHz | 10 Gbps | 100 m | SSTP/PiMF (each pair shielded) |
| Cat8 | 2000 MHz | 25–40 Gbps | 30 m | STP/SFTP required |
Which category to choose
| Use case | Recommended | Notes |
|---|---|---|
| Home network — gigabit | Cat5e or Cat6 | Either handles 1 Gbps. Cat6 preferred for new runs. |
| Home network — future-proofing | Cat6A | Supports 10G at full 100 m run, more headroom |
| Office / SMB structured cabling | Cat6A | Industry standard for new installations |
| Data center short runs | Cat8 | 25–40G, max 30 m only — not for long runs |
UTP vs STP vs SFTP
| Type | Description | When needed |
|---|---|---|
| UTP | Unshielded twisted pair | Standard home and office use, away from interference sources |
| STP / FTP | Overall foil shield around all pairs | Near power cables, industrial environments |
| SFTP / S/FTP | Per-pair foil + overall braid shield | High-interference environments; Cat7/Cat8 |
STP cables require grounded shielded connectors and shielded keystone jacks to be effective. An improperly grounded shield can worsen performance compared to UTP.
PoE (Power over Ethernet)
Cat5e and above support PoE. Higher power PoE standards (IEEE 802.3bt, up to 90 W) benefit from Cat6A cabling due to lower resistance and reduced heat buildup at higher current levels.
For any new home wiring, run Cat6A. The small cost difference over Cat6 gives 10 Gbps at full cable runs with room to grow. For simple patch cable replacement, Cat6 is fine.