What broadband speed do I need?

Broadband speeds are measured in megabits per second (Mbps). Download speed is how quickly data reaches you — loading web pages, streaming films or downloading games. Upload speed is how quickly you can send data — video calls, sending large files or backing up photos to the cloud.

Most deals have a much higher download speed than upload speed. That suits most households, but if you work from home, make lots of video calls or regularly upload large files, it's worth checking the upload figure as well. Full-fibre connections often offer faster upload speeds than older part-fibre lines.

The biggest factor is how many things happen at once. Each person streaming, gaming or on a video call takes a share of the connection, so a speed that's fine for one person can feel slow when the whole household is online in the evening.

As a rough guide, these are the kinds of activity that need more or less speed:

• Browsing, email and social media need relatively little speed
• Streaming in HD typically needs a few Mbps per stream; streaming services often suggest somewhere in the region of 15–25Mbps for each 4K stream
• Video calls need a steady connection in both directions, so upload speed matters as well as download
• Online gaming depends more on a stable, low-latency connection than raw speed, but game downloads and updates can be very large
• Smart home devices, phones and tablets all add to the load, even when they're just updating in the background

Under advertising rules, the headline speed in a broadband advert is an average: the speed that at least half of a provider's customers on that package get at peak time (usually the evening). Your own speed may be higher or lower, depending largely on your line and the technology used.

Before you sign up, a provider should give you a personalised speed estimate for your address. Providers signed up to Ofcom's voluntary code of practice on broadband speeds must also give you a minimum guaranteed speed. If your speed falls below that and the provider can't fix it within a reasonable time, you may be able to leave without a penalty.

The speed coming into your home is only part of the story. Wi-Fi signals weaken through walls and floors, so rooms far from the router may get much slower speeds than the line supports.

Before paying for a faster package, it can help to test your speed with a device plugged directly into the router using an Ethernet cable. If that's fast but Wi-Fi is slow elsewhere, moving the router somewhere central and raised, or using a mesh Wi-Fi system, may help more than upgrading. Older phones and laptops can also limit the speed you see.

Faster packages usually cost more, so it's worth matching the speed to your needs rather than picking the fastest available. Check what's available at your address, as full fibre, cable and part-fibre services vary from street to street.

If you're unsure, note what your household does during the busiest time of day and check the speed you get now. If it rarely causes problems, a similar speed may be enough. If you regularly see buffering or dropped calls, and Wi-Fi isn't the cause, a faster package may be worth comparing. Remember to look at the total cost over the contract, including any mid-contract price rises.