Why Your Wi-Fi Feels Slower Than Your Plan's Advertised Speed

You pay for 500 Mbps. Standing next to the router your phone reports 480. In the back bedroom it reports 90. Your ISP has not throttled you — the speed arrived at the router exactly as promised, and then your home network lost most of it.

The short answer

Your ISP guarantees speed to the router. Wi-Fi is a separate, shared, radio-based link that typically delivers 40-70% of your plan speed, and far less at distance or on 2.4 GHz.

Where the speed goes

1. The band you are on

This is usually the largest single factor. Modern routers broadcast on two or three bands with very different characteristics:

2.4 GHz is crowded — it shares space with Bluetooth, microwaves, baby monitors and every neighbour's network — and has only three non-overlapping channels. A device that has quietly fallen back to 2.4 GHz will never exceed about 10 MB/s no matter what you pay.

2. Distance and walls

Radio signal falls off with the square of distance, and every obstacle costs more. Rough penalties for a 5 GHz signal:

• Plasterboard wall: 10-20% loss
• Brick or concrete wall: 30-50% loss
• Floor or ceiling: 40-60% loss
• Anything with foil insulation or metal mesh: potentially total

3. The advertised Wi-Fi number is not a real number

A router sold as 'AX3000' is claiming 3,000 Mbps by adding together every band at once, under laboratory conditions, with no interference. No single device ever sees that. A realistic expectation is 40-60% of the per-band figure.

4. Wi-Fi is half-duplex and shared

Unlike Ethernet, only one device on a band can transmit at a time. Every device takes turns, and a single slow old device can hold up the queue for everyone — a phenomenon worth understanding if your network has a lot of clients, covered in how many devices can your internet support.

Diagnose it in five minutes

1. 1Test on Ethernet. Plug a laptop directly into the router and run a speed test. This is your true line speed — if it matches your plan, the ISP is fine and the problem is inside the house.
2. 2Test next to the router on 5 GHz. This is your Wi-Fi ceiling.
3. 3Test where the problem is. The gap between this and step two is what distance and walls are costing you.
4. 4Check which band you joined. Many networks use one name for both bands, and phones silently prefer 2.4 GHz when the 5 GHz signal weakens.
5. 5Convert to MB/s with the calculator so you can compare the result against what your downloads actually show.

What actually fixes it

Free

• Move the router. Central, elevated, out in the open. Not in a cupboard, not behind the TV, not on the floor.
• Split the bands into separate network names so you can choose 5 GHz explicitly on important devices.
• Change the channel. Use a Wi-Fi analyser app to find a quiet one, especially on 2.4 GHz.
• Update the router firmware.

Cheap

• Run Ethernet to whatever matters most — a desktop, a console, a TV. It is the only guaranteed fix.
• Powerline adapters where cabling is impractical. Slower than Ethernet, far more consistent than distant Wi-Fi.

Not cheap

• A mesh system for large or awkwardly shaped homes. Use one with a dedicated backhaul band or wired backhaul — otherwise each hop roughly halves throughput.
• A newer standard. Wi-Fi 6 and 7 genuinely help in device-dense homes, but only if your devices support them.

Set your expectations properly

Above roughly 300 Mbps, your Wi-Fi — not your ISP — becomes the limiting factor for most devices in most homes.

That is worth knowing before upgrading a plan: a gigabit connection reaching a 2.4 GHz laptop delivers the same 8 MB/s that a 100 Mbps plan would.