Think about peak simultaneous demand
The relevant question is not how many people live in your house. It is how many of them are doing demanding things online at the same time. If your five-person household tends to all be online in the evenings, that evening peak is what you need to plan for.
A real-world calculation for a busy evening
Two 4K streams: approximately 50Mbps combined. One person gaming: around 10Mbps. One video call: 5Mbps upload. General browsing across several phones and tablets: 15Mbps. Smart devices in the background: 10Mbps. Add a 20% buffer for headroom and you are looking at around 100-110Mbps download with meaningful upload demand. A 100Mbps package technically covers this, but 150-200Mbps gives comfortable headroom.
WiFi coverage is often the actual bottleneck
Before upgrading your broadband package, confirm that everyone in the house is actually receiving the speed they should be over WiFi. In a large home, rooms far from the router may be getting significantly reduced speeds regardless of what the broadband line delivers. A mesh WiFi system is often a more impactful investment than a faster package.
Why full fibre matters more in large households
FTTC connections are more susceptible to peak-time congestion, precisely the scenario that large households create most acutely. Full fibre handles simultaneous demand significantly more cleanly with consistent speeds during busy periods.
