Why is my speed test slower than my package?

Because the number on your bill is rarely a promise of “this speed every second on every device.” It might be a maximum, a range, or an average under ideal lab-style conditions. Real tests bump into Wi-Fi, old kit, other people’s traffic, peak-time congestion, and sometimes the limits of your actual line.

Common causes (work through in order)

  1. Wi-Fi: Distance, walls, and interference cap speed before the fibre does.
  2. Device: Cheap dongles, battery-saver modes, and busy CPUs skew results.
  3. Router: Older hardware or bad placement throttles everyone at once.
  4. Background traffic: Updates, cloud sync, and a quietly seeding game client eat Mbps.
  5. Peak time: Neighbourhood demand rises after school and work - especially in dense streets.
  6. Package wording: “Up to” and tier names do not map cleanly to every line.

If you already have a believable download Mbps and want a rough sense of how long a large file might take at that steady rate, try the download time calculator - real transfers still vary with Wi-Fi, servers, and contention.

When to contact your provider

When a fair wired test on a capable PC, repeated across days, still sits far below what your paperwork implies - and you have dates and screenshots. A single phone test from the garden office is not that evidence.

Typical UK scenarios

In a converted Victorian flat in Edinburgh, thick walls might cap Wi-Fi at 45 Mbps while the same socket’s Ethernet run hits 900 Mbps on a full-fibre tier - the “slow package” was never the exchange.

In a new-build near Reading, a family sees tests fall only between 6 and 9 p.m. That pattern points to busy-hour sharing on the network, not a broken router, especially if daytime wired tests look fine.

What Pulse can and cannot confirm

Pulse shows what your browser session achieves for download, latency, and jitter - it helps you document behaviour over time. It does not read your contract or know your cabinet’s spare capacity; use it as structured evidence, not a verdict.

Run the Pulse speed test · Read methodology · Review privacy

FAQ

Is my ISP lying if the test is below the headline number?

Not necessarily. Marketing numbers rarely describe your worst Wi-Fi corner at peak time.

Why does Ethernet matter for this question?

It removes Wi-Fi as a suspect. If wired tests match the package and wireless does not, the fix is usually in the home.

Could I be reading the wrong tier on my bill?

Yes - check whether you are on a discounted tier, a speed-capped product, or an older sync profile.

When should I involve my provider?

After fair wired tests at different times still sit far below what your contract suggests, with notes to hand.

Sources and review notes

Last reviewed: 11/04/2026 · Written by: Dr Alex J Martin-Smith (LinkedIn)

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