How much data does 4K streaming use?

GB per hour by quality

Netflix publishes data use per hour for each quality setting. For services that only publish a recommended connection speed, data per hour follows from the bitrate:

GB per hour = Mbps × 3,600 ÷ 8 ÷ 1,000 = Mbps × 0.45

The calculated rows assume the stream uses the full recommended speed every second, so they are upper limits. Streaming is almost all download: the upload side of a video stream is tiny.

Why real usage is often lower

Both kinds of figure are ceilings rather than predictions. Netflix states its numbers as "up to" values, and a recommended connection speed is what a service asks for to play smoothly, not a measured average. Actual use depends on:

• Adaptive streaming. Streaming apps change quality with the connection, so a stream does not always run at its top setting.
• Screens and settings. Netflix and YouTube both let you choose a lower quality or a data-saving setting, and the quality you get also depends on your plan and device.

So plan with the ceiling if you are near a data cap, and expect real bills to come in at or under it.

Monthly totals and data caps

Multiply GB per hour by hours per day and days in the month (an average month is about 30.4 days):

Against a 1.2 TB (1,200 GB) monthly cap, Netflix 4K at up to 7 GB per hour allows about 171 hours, or 5.6 hours a day; at 9 GB per hour, about 133 hours, or 4.4 hours a day, before anything else is counted. A household with two TVs, games and backups reaches a cap much sooner. The data usage calculator adds every activity together and compares the total with your cap, and TB per month to Mbps shows that 1.2 TB a month is the same as only about 3.65 Mbps running around the clock.

4K on mobile data and hotspots

Mobile allowances are much smaller, so 4K empties them quickly. A 10 GB allowance lasts about 1 h 26 min at Netflix's 7 GB per hour for 4K, or 1 h 7 min at 9 GB per hour. Netflix HD at up to 3 GB per hour stretches the same 10 GB to about 3 h 20 min, and SD at up to 1 GB per hour to about 10 hours. If you stream to a laptop over a hotspot, set the quality manually in the app so it does not pick a higher setting than you want.

Data and speed are different questions

Data use is how much arrives over a month; speed is how much arrives per second. A 4K stream needs a connection of about 15–20 Mbps while it plays, so four of them at once fit on a 100 Mbps plan (see is 100 Mbps fast?), while its monthly data depends only on how many hours you watch. To size a plan for everything your household runs at once, use how much internet speed do I need; the per-activity figures are listed in internet speed by activity. For converting any rate between Mbps and MB/s, the bytes to Mbps converter shows every unit.