Most people are sold more speed than they use, and some are sold too little. Count what actually happens at the same time in your home at the busiest moment of the evening, and this calculator turns it into a download and upload figure you can compare with your plan.
Then test your speed to see what your line really delivers. Test wired if you can, because Wi-Fi hides the true figure.
These are per-activity allowances, deliberately on the generous side so that one stream doesn't stutter when another starts. They are the same figures used across our guides.
| Activity | Download | Upload |
|---|---|---|
| 4K stream | 25 Mbps | – |
| HD stream | 10 Mbps | – |
| Video call (HD) | 5 Mbps | 5 Mbps |
| Online gaming | 3 Mbps | 1 Mbps |
| Browsing / social media | 2 Mbps | 0.5 Mbps |
| Big download or cloud backup | 50 Mbps | 10 Mbps |
Streaming services publish lower minimums than this. Netflix, for example, lists around 15 Mbps for 4K. We use 25 because a stream that only just fits drops quality as soon as anything else happens on the line.
The calculator then doubles the total. That margin covers Wi-Fi losses, background updates, phones syncing photos and the evening slowdown most providers have. It is the same rule of thumb as in our guide to how much speed you need.
An online match uses very little bandwidth, usually well under the 3 Mbps allowance here. What ruins a game is latency, jitter and packet loss, and a faster plan does not fix any of them. If gaming is the problem in your home, read Mbps vs ping and jitter and packet loss before you upgrade.
Download speeds have grown fast; upload often hasn't. Cable plans commonly offer a tenth as much upload as download. Two people on video calls while a phone backs up photos can fill a 20 Mbps upload on its own, and when upload is full, calls freeze and even browsing feels slow. If the upload figure above is higher than your plan's, that is the number to take to your provider, not the download one.