What this calculator does
Data use is hours multiplied by a rate for each activity, added together. Video is the dominant term by a wide margin: standard-definition streaming runs around 1 to 1.5 GB an hour while browsing is closer to 0.06 and music around 0.12.
That factor of twenty-five between browsing and video is why plans are consumed by a small number of activities. An hour of browsing, an hour of music and an hour and a half of video comes to 2.3 GB a day, of which video is 2.25. Everything else is rounding.
The formula
Each activity contributes its hours multiplied by its GB per hour rate, and the three are added to give a daily total. The monthly projection multiplies by 30. The days-until-cap figure divides the plan cap by the daily use. Rates vary considerably with quality settings, which is the main source of uncertainty.
| Term | Meaning |
|---|---|
| GB per hour | The consumption rate for an activity. Video varies from about 0.7 GB at low quality to 7 GB at 4K. |
| Browsing | Web pages and social media, around 0.06 GB an hour, though video-heavy feeds are far higher. |
| Streaming music | Around 0.05 to 0.15 GB an hour depending on bitrate. |
The inputs explained
| Field | What to enter |
|---|---|
| Browsing & social media (hours/day) | Hours of browsing per day. |
| Browsing rate (GB/hour) | GB per hour for browsing. 0.06 is typical for text and images. |
| Video streaming (hours/day) | Hours of video streaming per day. |
| Streaming rate (GB/hour) | GB per hour for video. About 0.7 for low quality, 1.5 for standard definition, 3 for HD and 7 for 4K. |
| Music / audio streaming (hours/day) | Hours of music streaming per day. |
| Music rate (GB/hour) | GB per hour for music. 0.12 is typical at a standard bitrate. |
| Monthly data cap (GB) | Monthly data allowance in GB. |
When to use it
Choosing a plan
Estimating from actual habits gives a better basis for a plan size than guessing, and the projection against a cap shows whether it fits.
Diagnosing why the allowance ran out
The biggest contributor line usually answers it immediately, and it is almost always video.
Working out what to change
Dropping video quality from HD to standard halves the largest term, which is the single most effective change available.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How much does video streaming dominate?
A fixed amount of browsing and music with video hours increasing.
| Video hours per day | Daily data use | Projected monthly use | Days until the cap is reached | Biggest contributor |
|---|---|---|---|---|
| 0.5 h | 0.93 GB | 27.9 GB | 53.8 days | Video streaming |
| 1 h | 1.68 GB | 50.4 GB | 29.8 days | Video streaming |
| 2 h | 3.18 GB | 95.4 GB | 15.7 days | Video streaming |
| 4 h | 6.18 GB | 185.4 GB | 8.1 days | Video streaming |
Questions
How much data does video streaming use?
Roughly 0.7 GB an hour at low quality, 1.5 at standard definition, 3 at HD and up to 7 at 4K. The quality setting is the single biggest lever on mobile data use, and most services let you cap it separately for mobile networks.
Why is my actual usage higher than estimated?
Usually background activity: app updates, cloud photo backup, automatic video playback in social feeds and location services all consume data without being noticed. Autoplay video in a social feed is a particularly common and invisible drain.
Does wifi use count?
Not against a mobile allowance. This calculation covers whatever hours you enter, so enter only the time spent on the mobile network. Time on wifi is unlimited from the plan point of view.
What uses the least data?
Text-based activity: messaging, email and reading web pages. Music streaming is modest at around 0.12 GB an hour. Downloading content over wifi for offline use afterwards removes it from mobile data entirely, which is the most effective single change for heavy video users.
For file transfer times, see the file transfer speed calculator. For binge-watching time rather than data, see the binge-watch planner.