Walk into any low-voltage supply house and you'll see Cat5e, Cat6, and Cat6a sitting on the same shelf, often within a few dollars of each other per thousand feet. The labels make it look like a simple upgrade path, but the right pick depends on the run length, the bandwidth your customer is paying for now, and what they're going to ask for in three years. Here is the practical breakdown installers actually need.
Cat5e is rated for 1 Gbps over 100 meters and tops out at 100 MHz. It is still spec-compliant for almost every home and small-office gigabit drop, and it is the cheapest cable you can pull and still meet TIA-568 standards. If your customer has a 1 Gbps internet plan, gigabit switches, and no plans to push beyond that, Cat5e is not wrong. It is just not future-proof.
Cat6 doubles the bandwidth headroom to 250 MHz and supports 10 Gbps, but only on runs up to 55 meters. For full 100-meter 10G runs you need Cat6a. In practice, Cat6 hits the sweet spot for most commercial gigabit installs where runs stay under 55 meters, you want a margin of safety on crosstalk, and the customer might add a few PoE+ cameras or APs later. The cable is stiffer than Cat5e, so plan termination time accordingly.
Cat6a is the right answer when the spec sheet calls for 10G, when PoE++ Type 4 up to 90W is on the table, or when the customer expects to support 802.11ax or 802.11be access points at full throughput. The 500 MHz bandwidth and tighter alien crosstalk performance are the real benefit. The trade-offs are real too. Thicker jacket, larger bend radius, more conduit fill, and slower terminations. Plan your pathways before you buy a box.
Quick decision rules we use in the field. Residential gigabit, runs under 100m, no PoE cameras planned: Cat5e is fine. New commercial build, expect to be there 5+ years, mixed PoE: Cat6 minimum, Cat6a if budget allows. Anything labeled 10G, multi-gig WiFi, or PoE++: Cat6a, no exceptions. And whatever you pick, match the jacket rating to the space. Plenum CMP goes in air-handling spaces. Riser CMR goes between floors. General-purpose CM is for everything else. Mismatching jacket ratings is the fastest way to fail an inspection.
Rack IT stocks all three categories in CM, CMR, and CMP jackets, in 1000-foot pull boxes and bulk reels. Trade accounts get tiered pricing on full-pallet orders. Ask about volume tiers when you set up your account.