Bandwidth is the easiest thing to oversell, because more always sounds safer and nobody gets blamed for buying too much. But an oversized circuit is money leaving every month for capacity that never gets used.
Start with concurrent users, not headcount
Twenty staff does not mean twenty simultaneous heavy users. Ordinary office work — email, documents, browsing, a few cloud apps — consumes far less than people assume. The load comes from specific activities, not from bodies at desks.
Count the heavy things
- Video calls — roughly 2–4 Mbps each for HD, and they need consistency more than volume.
- Cloud backup and sync — can saturate a circuit entirely if unscheduled. Often the real culprit behind "the internet is slow at 5pm."
- Large file transfers — design, video, CAD, medical imaging. These set your ceiling.
- Hosted services — anything you serve to the outside world makes your upload speed the number that matters.
Why symmetry matters more than the headline number
Consumer-style connections give you a large download and a small upload. The moment you host anything, run VoIP, or back up to the cloud, upload becomes your bottleneck. A symmetrical 200 Mbps circuit will out-perform an asymmetric "500 Mbps" one for most business workloads.
A workable approach
- Add up your realistic simultaneous heavy usage.
- Add comfortable headroom — roughly double — so peaks do not hurt.
- Confirm the circuit is symmetrical.
- Check what an upgrade costs and how quickly it can happen.
That last point matters most. On fiber, moving from 200 Mbps to 500 Mbps is often a configuration change rather than a new install. Buying a right-sized circuit you can grow beats buying three years of headroom up front.
