How much mobile data you need per month depends almost entirely on one thing: how many hours of video you watch on mobile data, and at what quality.
Everything else, messaging, maps, music, browsing, adds up to a fraction of that. A person who never watches video away from Wi-Fi can live on a small plan; a person who watches an hour of HD video on the train every day needs a plan measured in tens of gigabytes.
The fastest way to get your own number is our data usage calculator: set the hours per day for each activity and it produces a monthly figure. Below is what sits behind that figure, where the surprises come from, and what a VPN does to it.
SD 480p ▇ 0.7
HD ▇▇▇▇ 3
4K ▇▇▇▇▇▇▇▇▇ 7
└─ from our own calculatorHow much data video uses: SD, HD and 4K
The calculator's video row assumes roughly 0.7 GB per hour at standard definition, about 3 GB per hour at HD, and about 7 GB per hour at 4K. Those are the figures that swing a monthly total from a few gigabytes to a hundred. The same one-hour show costs four times as much in HD as in SD, and ten times as much in 4K, and on a phone screen the difference between SD and HD is far smaller than the difference in your bill.
If you take one thing from this article: the video quality setting in your apps, not the number of apps you use, is what decides your plan.
standard quality || high quality |||| very high quality |||||||||| └─ every other category together rarely matches one of these
How much data music, calls and browsing use
Music barely registers next to video: an hour of listening costs you closer to a few minutes of HD video than to an hour of it. Video calls land between the two, and the camera on both sides matters far more than the length of the call; audio-only calls are cheap. Social feeds and browsing are unpredictable for one reason: autoplaying video. A feed with autoplay on behaves like low-quality video; the same feed with autoplay off behaves like text and photos. Maps are small once the area is downloaded offline. Gaming itself is small; game downloads and updates are large, and they're the usual culprit when a plan disappears overnight.
messaging and mail almost nothing maps and navigation small social feeds moderate music streaming moderate video calls large
How much data you need per month: three steps
- For each activity, be honest with yourself about hours per day on mobile data, not total hours. Most of your video happens on home Wi-Fi and doesn't count.
- Multiply by the per-hour figure for that activity and by the days in a month. The calculator does this for you and lets you change the video quality separately.
- Add about a third on top. That margin is there for background activity and the surprises below, and a plan that's slightly too big costs you less than the overage on one that's slightly too small.
1 reset the counter today 2 live a normal week 3 multiply by four, add a margin └─ guessing from a table never beats one week of your own data
What uses mobile data unexpectedly
Photo and video backup on mobile data. A phone that shoves every photo into the cloud the second you take it can burn more in one day at the beach than in a week of messaging. Set backup to Wi-Fi only and forget about it.
Autoplay. Feeds, shopping apps and news sites will play video at you without asking. Turn autoplay off on mobile data in every app that gives you the setting.
App and system updates. One system update over mobile data can be bigger than a month of your browsing. Keep updates on Wi-Fi.
Hotspot. A laptop tethered to your phone behaves like a laptop, not like a phone: cloud sync, updates and video calls at desktop quality. Hotspot days are the days most people blow through the whole plan.
Background refresh. Dozens of apps quietly phoning home add up to a small but permanent drip, and the only real cure is turning background data off for the ones that don't need it.
How much data a VPN adds
A VPN adds a small overhead to every packet, because the encryption wraps your traffic in another layer. For ordinary use the addition is a few percent, not a doubling, and video quality settings matter a hundred times more. Where it can matter is in what the tunnel does when it's unstable: reconnections and retries cost data too. The measurement and the ways to keep the overhead small are in Does a VPN use more data.
roaming is priced per megabyte video becomes the entire bill offline maps remove a daily cost └─ download maps and music before you leave, not on arrival
How much data you need when traveling
Roaming packages and travel eSIMs are sold by the gigabyte, so the estimate matters more abroad than at home. Two things change on a trip: maps run more, and photos upload more. Two things help: download offline maps and an offline translation pack before you leave, and set every backup and update to Wi-Fi only. Which line to use in a country that filters the internet, and how it interacts with a VPN, is a separate question, covered in eSIM, roaming or a local SIM in China and, more generally, in Do I need a VPN when traveling.
autoplay video in feeds photo and cloud backup on mobile app updates outside Wi-Fi high-quality music by default └─ four settings, most of the bill
A table can't know your habits. Describe a normal week.
Help me size a mobile data plan for myself.
A normal week: video (how much, what quality),
music (how much), social feeds (how much),
video calls (how often), maps and messaging
(constantly / rarely).
Wi-Fi available: (at home and work / rarely).
Phone backs up over mobile: (yes / no / not sure).
Estimate a monthly figure with a sensible margin,
and say which two settings would move it most.
Do not push me towards a bigger plan than the
numbers justify.How to use less mobile data
Drop video to standard definition on mobile data and leave HD for Wi-Fi. Turn autoplay off. Move backups and updates to Wi-Fi. Download music and maps at home. Use the phone's built-in data saver, which does most of this in one switch. None of it changes what you can do; it changes when the bytes are spent.
404 VPN's data usage calculator runs in the browser, with nothing sent to a server, and tells you at the end whether our free plan, 2 GB a day, covers your usage or whether you need more. If you're choosing a mobile plan and a VPN at the same time, start with the calculator, then read about the free plan on the home page.
