Short answer: add up what your household does online at the same time, then add some headroom. For many homes that lands around the FCC’s broadband benchmark of 100 Mbps download and 20 Mbps upload. Faster plans mainly help when you move large files or have several wired devices that can actually use the speed.
What common activities need
Video streaming is usually the biggest steady use. Netflix recommends 3 Mbps or more for HD (720p), 5 Mbps for Full HD (1080p) and 15 Mbps for 4K, per stream. Web browsing, email and music use far less, and big downloads simply finish faster on faster plans.
Add it up
The FCC benchmark
In its 2024 broadband report, the FCC raised its benchmark for high-speed fixed broadband from 25/3 Mbps to 100/20 Mbps. It’s a useful reference point for a modern household, not a requirement.
When a faster plan makes sense
Gigabit and multi-gig plans help with large downloads and uploads, cloud backups, and several heavy users at once. But your equipment has to keep up. gFiber, for example, recommends a router with a 1 Gbps internet port for its 1 Gig plan and a 10 Gbps port for its multi-gig plans. See 2.5G, 5G and 10G Ethernet and the best routers for multi-gig internet.
Wi-Fi is often the limit. Intel rates its two-stream Wi-Fi 7 laptop adapter at up to 5.8 Gbps, and only with 320 MHz channels and 4096-QAM, conditions that need the device close to the router. Most phones and laptops get far less in real use, so a multi-gig plan mostly benefits wired devices.
Speed isn’t the same as responsiveness
If games lag or video calls stutter, more speed may not help. The usual cause is latency under load, where a busy connection delays everything else. See how to reduce ping and lag. If your connection is slower than your plan over Wi-Fi, start with slow Wi-Fi fixes.