Advertised speed vs real speed: why numbers differ

Providers advertise up to speeds, but real throughput varies. Learn the causes of the gap and how to judge your own connection fairly.

The speed on your plan is a maximum, often described as up to a figure. Real speeds depend on many things.

Reasons for the gap

• Units. Plans use megabits, and downloads show megabytes. See the conversion table.
• Protocol overhead. Some of every packet is addressing and control data, not your file.
• Wi-Fi. The wireless link is often slower than the plan.
• Shared links. In many networks, neighbors share capacity at busy times.
• Servers. The remote side may throttle or be far away.
• Your device. Old network adapters and busy PCs cannot always keep up.

A fair way to test

1. Connect a PC by cable.
2. Close other apps and pause other devices.
3. Run a speed test at several times of day.
4. Note the best and worst results.

If results sit close to your plan, the plan is working. If they are far below at all times, ask your provider, and bring your results.

Everyday readings are different

A live readout during normal use will usually show less than your plan, because most activities do not need all of it. Streaming a video might use a few MB/s. That is fine.

What is a good speed?

It depends on what you do and how many people share the connection. See what is a good internet speed? and how to check network speed on Windows.

NetSpeedDisplay is a meter, not a test. It shows what is moving, so you can tell whether low speeds come from your plan or from how little is being asked of the connection.

Related pages

Published 2026-10-17