You size the switches, spec the router, maybe budget for a firewall, and the cabling almost picks itself at the end. Yet it’s the one part of the network you choose last and live with longest: the kit plugged into it gets swapped every few years, while the cable in the walls and risers tends to stay put for a decade or more.
That makes the category you choose now a decision that potentially lasts you for a long time. Cat6 has become the default for most new business installs, and Cat6A is the fastest-growing part of the market as 10 Gigabit Ethernet and Power over Ethernet spread into more offices. Get the category right up front, and you land the performance you need without paying for headroom you’ll never touch, or worse, re-pulling cable through a live building a few years on.
So what Ethernet cable do you need? This guide compares Cat5e, Cat6 and Cat6A on the things that actually decide it, speed, bandwidth, distance and cost, so you can match the cable to the job first time.
Why Cable Category Is Important
The category stamped on the cable, be it Cat5e, Cat6 or Cat6a, is a performance class set by international standards. It establishes three things before you plug anything in: the top speed the cable can carry, the bandwidth it runs at in megahertz (MHz), and the distance it can hold that speed over. A higher category lifts all three.
Active kit tends to get replaced on a three-to-five-year cycle, while the cabling behind the faceplate often stays put for longer. The sums are lopsided too: the price gap between categories runs to a few pounds per box, whereas getting it wrong is measured in a day’s labour pulling fresh cable through a live building, plus the disruption of doing it around people trying to work. Spend a little more on the category now, and you rarely regret it. Under-spec it, and the bill turns up later and larger.
Cat5e vs Cat6 vs Cat6A, Compared
Line the three up and it’s a steady climb, each category lifting speed, bandwidth and reliable distance over the one before:
- Cat5e is the long-standing workhorse. It carries Gigabit Ethernet (1 Gbps) at 100 MHz, which is plenty for VoIP handsets, a handful of PCs and general office traffic.
- Cat6 steps up to 250 MHz with tighter internal construction that cuts crosstalk. That extra headroom is the real change in Cat5e vs Cat6, and it’s what lets Cat6 reach 10 gigabit speeds Cat5e simply can’t.
- Cat6A runs at 500 MHz and is built to hold 10 gigabits across a full 100-metre run, which is where it pulls ahead of standard Cat6.
That last point is where Cat6 vs Cat6A gets interesting and where a lot of spec sheets get read wrong. Cat6 will do 10 Gigabit, but only over shorter runs, up to around 55 metres in good conditions and less where there’s more interference. Cat6A holds the same speed end to end.
If your longest runs are short, Cat6 may already get you to 10 gigabits. If they’re long, Cat6A is the one that guarantees it across the full 100 metres.
The trade-off is physical. Cat6A cable is thicker and stiffer, it’s often shielded, and it needs a larger bend radius and more care to terminate. It fills trunking faster and takes a little longer to install, which feeds the cost gap as much as the price of the reel does. None of that rules it out, but it’s worth knowing before you commit a whole building to it.
Which Cable Suits Which Setup
The right category is really a question of what the network has to do, not how big the building is. Three common setups cover most businesses.
A small office or single comms point running VoIP phones, a few PCs, a printer and some CCTV isn’t stretching any of these cables. Cat5e handles that comfortably, and for years it was the obvious pick. These days, with the price gap so small, most installers default to Cat6 even here, purely for the headroom it buys against whatever gets added next.
A growing business is where Cat6 thrives. Once you’re running Power over Ethernet to wireless access points and cameras, adding more devices per desk, and leaning on the network for cloud and video, the extra bandwidth stops being a nice-to-have. For most Ethernet cables for business going in today, Cat6 is the sensible middle ground: real 10 Gigabit capability on shorter runs, at a price that doesn’t sting.
A data centre, server room or high-density install is Cat6A territory. When you need guaranteed 10 gigabits across full-length runs, dense Power over Ethernet, or the reassurance of shielded cable in an electrically noisy room, Cat6A is the category specified for the job.
Future-Proofing: When Cat6A Feels Like the Right Fit
Cat6A isn’t always necessary, and paying for it out of habit is its own kind of waste. What’s changed is how fast the demands are climbing. The newest Wi-Fi 7 access points ship with 2.5 and even 10 gigabit uplink ports, so feed one with a gigabit-era run, and the cable, not the kit, becomes the bottleneck.
That’s the case for a cat6A Ethernet cable: it carries 10 Gigabit across a full 100-metre run and handles the higher-power Power over Ethernet that modern access points and cameras draw. If your runs are short and the site won’t push past gigabit for years, Cat6 is the sensible choice, and there’s no need to gold-plate it. But where the runs are long, the density is rising, or you’d rather not open the walls again soon, Cat6A is the category that buys you room to grow.
The Quick Recommendation
If you take nothing else away, here’s the whole comparison at a glance:
| Cat5e | Cat6 | Cat6A | |
| Max speed | 1 Gigabit | 10 Gigabit | 10 Gigabit |
| Bandwidth | 100 MHz | 250 MHz | 500 MHz |
| 10-gigabit distance | Not supported | Up to ~55m | Full 100m |
| Best for | Basic office, VoIP, CCTV | Most new business installs | Data centre, dense PoE, 10GbE to the desk |
| Relative cost | £ | ££ | £££ |
The rule of thumb is simple. Cat5e still handles the basics, Cat6 is the sensible default for most new installs, and Cat6A is the one to specify when you need guaranteed 10 gigabits or you’re future-proofing a site you’d rather not rewire. When a job sits between two categories, go with the higher one. The headroom rarely goes to waste, and it’s a lot cheaper than pulling the cable again later.
Find the Right Cable for Your Network
Whichever way your setup leans, the category is the decision worth getting right first, because it’s the part you’ll live with long after the switches have been swapped. Match it to the job in front of you, leave a little room to grow, and the cabling stops being the thing that holds your network back.
When you’re ready to choose, you’ll find Cat5e, Cat6 and Cat6A together across our full range, from patch leads and bulk reels to modules and patch panels. Not sure which category fits your kit? Get in touch and our team will help you spec it.
And for a closer look before you buy, head over to the Comms Express YouTube channel for product walkthroughs across the range.
