Internet speed needed by activity

Speed needed for each activity

Figures are per simultaneous use. Two people watching separate 4K streams need 2 × 20 = 40 Mbps; one stream watched by two people on the same TV needs 20. To total them for your home, the internet speed calculator adds up everything that happens at the same time, adds headroom and suggests a plan tier.

The source column refers to the download figure unless the notes say otherwise; for live streaming it refers to the upload figure. Figures checked 26 September 2026.

Why we use 20 Mbps for 4K, not 15

The two biggest video services publish different numbers. Netflix recommends 15 Mbps for 4K (Ultra HD), while YouTube recommends 20 Mbps for 4K. Both use adaptive bitrate: the player picks a quality based on the speed it measures and moves up or down during playback. A recommendation is the speed at which the top quality should play without dropping down.

We use 20 Mbps because the calculators are meant to say "enough", not "just about enough". The gap is 5 Mbps per stream, which only matters with several 4K screens at once:

If your household only watches Netflix, the 15 Mbps figure is fine to use, and four 4K streams fit in 60 Mbps rather than 80.

How the GB-per-hour column is worked out

Speeds are in megabits per second; data caps are in gigabytes. To convert an hour of use at a steady rate:

GB per hour = Mbps × 3,600 s ÷ 8 bits per byte ÷ 1,000 MB per GB
            = Mbps × 0.45

We add download and upload together, because most data caps count both. A 1080p Zoom call is (3.8 + 3.0) × 0.45 = 3.06 GB per hour; a 4K stream is 20 × 0.45 = 9 GB per hour.

Treat this column as an upper bound. Streaming services lower the bitrate on small screens and in simple scenes, and video calls send less when a camera is off or the picture is still. The data usage calculator uses the same formula with 30.4 days per month.

Worked example: a month of evening TV

• 4K: 9 GB/h × 2 h × 30.4 days = 547.2 GB
• 1080p: 2.25 GB/h × 3 h × 30.4 days = 205.2 GB
• Total: about 752 GB a month, at most

On a plan with a 1 TB (1,000 GB) monthly cap, video alone would use about three quarters of it, before calls, games and updates.

The rows that are our estimates

Not every activity has an official figure. Browsing, music, gaming traffic, security cameras and idle devices are our estimates, labelled in the table. They are deliberately generous and small next to video:

• Browsing arrives in bursts. We budget a steady 1 Mbps per person, which covers typical page loads without pretending to know exact page sizes.
• Online gaming sends very little game data. The 3 Mbps down and 1 Mbps up budget mostly covers voice chat. What matters for games is ping, covered in latency vs bandwidth.
• Cloud cameras upload continuously while recording, which is why they appear in the upload column at 2 Mbps each.
• Idle devices add up only in large numbers: ten of them come to 1 Mbps down and 0.5 Mbps up.

Game downloads and system updates are not in the table because they use whatever speed is available. The internet speed calculator handles them with an optional "download X GB in Y minutes" target instead. Every formula and estimate is listed on the methodology page.

Worked example: a couple on a weeknight

One person is on a 720p video call, the other watches 4K, a 1080p stream plays in another room, two people browse, and six idle devices sit on the network.

The next common plan tier at or above 39.3 Mbps is 50 Mbps. To check it the other way round, from a plan you already have, use what can my speed handle; for households that stream or back up a lot, the upload speed calculator sizes the upload side.