If your phone plan gives you 10GB of data a month, how many Netflix movies can you watch on it? The answer changes by 18 times or more depending on which mobile data usage setting you pick in the app.
The four settings Netflix describes
Netflix Help Center's data usage page divides the mobile app settings into four. The Korean version says Automatic uses 1GB for about 4 hours of viewing and Save Data uses 1GB for about 6 hours. For Maximum Data it says 1GB may be used for 20 minutes, with slight differences depending on your device and network speed. The fourth option, Wi-Fi Only, does not stream over mobile data.
The English version of the same page is clearer about Maximum Data: “Can use 1 GB per 20 minutes or more.” In other words, 1GB per 20 minutes is not a ceiling. Both versions recommend this setting only if you have an unlimited data plan.
Converted to usage per hour
We converted each description into usage per hour and applied it to a two-hour movie and a 10GB monthly allowance. 1GB is counted as 1,000MB. These are the page's approximate figures divided as written, so actual usage varies by title and device.
| Setting | Netflix's wording | Per hour (GB) | One 2-hour movie (GB) | Viewing time on 10GB |
|---|---|---|---|---|
| Save Data | 1GB per 6 hours | about 0.17 | about 0.33 | about 60 hours |
| Automatic | 1GB per 4 hours | 0.25 | 0.5 | about 40 hours |
| Maximum Data | 1GB per 20 minutes or more | 3 or more | 6 or more | 3 hours 20 minutes or less |
As an average transfer rate, that is about 0.37Mbps for Save Data, about 0.56Mbps for Automatic, and 6.7Mbps or more for Maximum Data (GB per hour × 8,000 ÷ 3,600 seconds). The hourly gap between Maximum Data and Save Data is 3GB versus about 0.17GB, or 18 times.
Choosing by plan size
On a plan with a fixed allowance, multiply your monthly viewing hours by the hourly usage and compare the result with the data you have left over. One hour a day for 30 days comes to about 5GB on Save Data, 7.5GB on Automatic, and 90GB or more on Maximum Data.
- If you have less than 7.5GB left each month, an hour a day on Automatic will not fit, while Save Data (about 5GB) will.
- If you have 7.5GB or more to spare and watch around an hour a day, Automatic fits too.
- Consider Maximum Data only on an unlimited plan. On 10GB it will not last beyond 3 hours 20 minutes.
Plans that throttle speed after the allowance runs out need a different calculation. For example, with a 400kbps cap like the Korean MVNO data safety option, the speed barely exceeds Save Data's average of about 0.37Mbps. Netflix only gives average hourly usage, so these pages cannot tell you whether playback will run without buffering at that speed.
When the setting won't change or doesn't apply
The same page adds two conditions. If you have set a per-profile data usage setting on the web, streaming on mobile devices won't exceed that setting. For instance, if the web setting is Low (up to 0.3GB per hour), choosing Maximum Data in the app will not use more. You also can't change the setting while Automatic is on or while downloads are pending. If the options are grayed out, turn off Automatic or let pending downloads finish, then choose again.
The app's download settings have a separate Wi-Fi Only switch. With it on, downloading titles does not use mobile data.
Keep the web settings' 4K figure separate
On the web settings, High quality uses up to 1GB per hour for SD, up to 3GB for HD, and up to 7GB for Ultra HD (4K). On a phone, Maximum Data means the highest quality for your device and the title you are watching. Neither the Korean nor the English version of the page says whether that setting reaches 4K's 7GB per hour on a phone. To see what one title actually uses on your phone, compare the data usage screen on your phone or in your carrier's app before and after watching.