When using Netflix, video quality directly affects data usage. Standard Definition (SD) uses about 1 GB per hour; High Definition (HD) about 3 GB per hour.; 4K uses about 7 GB per hour.
Adjusting the data usage settings within your Netflix account is the easiest way to control the amount of data used while watching Netflix. Data usage settings may only be changed from a computer, and will apply to all devices currently attached to your Netflix account.
Be aware of two factors:
Netflix has an
Auto
setting. If selected, Netflix will deliver the optimal quality setting based on the speed of your Internet connection. So if you have a very fast connection, Netflix will deliver a higher quality signal
If you upgrade your Internet speed, your data usage may increase. This is because the faster speed allows for a higher quality image, which in turn consumes more data