Enter your plan and active devices.
Network & guides
Wi-Fi Speed Guide / Calculator
See how much of your plan each device really gets over Wi-Fi once overhead and everyone else's use are taken into account.
Short answer: Wi-Fi shares one pool of speed between all active devices, and some of it is lost to overhead. Take your plan, multiply by Wi-Fi efficiency (around 60 to 80%) and divide by the devices that are really busy.
Why Wi-Fi is slower than the plan
Wi-Fi uses radio waves, and walls, distance and neighbours' networks all get in the way. On top of that, only one device can talk at a time, so busy devices take turns. A 200 Mbps plan with 70% efficiency leaves about 140 Mbps to share.
Example
200 Mbps plan, 70% efficiency, 5 active devices: 200 × 0.7 ÷ 5 = 28 Mbps each. That is enough for a 4K stream on every device. With 12 active devices it is about 11.7 Mbps each, still fine for HD but tight for 4K.
What counts as an active device?
A phone sitting on a table is not active. A TV streaming, a laptop on a call and a console downloading are. Count only what is busy at the same time.
Quick ways to improve Wi-Fi
- Put the router in a central, open spot, off the floor.
- Use the 5 GHz band for nearby devices and 2.4 GHz for distant ones.
- Use a cable for TVs, consoles and desktops.
- Consider a mesh system if the house is large.
Not sure what plan size to aim for? Try the Internet Speed Requirement Calculator.
FAQ
Frequently asked questions about the Wi-Fi Speed Guide / Calculator
Why is my Wi-Fi slower than my plan?
Distance, walls, interference and overhead all reduce it, and the speed is shared across your devices. A cable test shows the true plan speed.
What Wi-Fi efficiency should I use?
70% is a fair default. Use 50% in a big house with thick walls and 85% in a small flat close to the router.
Does more devices mean slower Wi-Fi?
Only when they are active together. Idle devices barely use any capacity.
Is 5 GHz better than 2.4 GHz?
5 GHz is faster but covers less distance. 2.4 GHz travels further but is slower and more crowded.
KEEP GOING
Related tools
Ping & Latency Information Tool
Enter your ping, jitter and packet loss to see how your connection will feel for gaming, video calls and browsing.
Use this toolNetwork Speed & Connection Guide
A step-by-step checklist for finding out why your internet feels slow, and what to try before calling your provider.
Use this toolInternet Speed Calculator
Type in your download, upload and ping and get a plain-English verdict, a score out of 100 and what your line can really handle.
Use this toolDownload Speed Calculator
Worked out how long a file took to download? Get your real speed in Mbps and MB/s, and see how it compares with your plan.
Use this toolUpload Speed Calculator
Know how long an upload took? Turn the file size and time into your real upload speed and see how it compares with your plan.
Use this toolMbps to MB/s Converter
Turn megabits per second (what your plan says) into megabytes per second (what your downloads show). Instant, no button needed.
Use this toolResults are estimates for planning. Last reviewed 2 October 2026.