How much data does a video call use?

Bandwidth is speed, data is volume

Zoom and Google publish their figures in megabits or kilobits per second, which is how fast data has to flow, not how much you use. The conversion is simple: 1 Mbps held for an hour is 450 MB. A call needs data in both directions, your video going out and the other person's coming in, so the two figures add up.

Keep in mind what these numbers are. Zoom calls them recommended bandwidth and Google describes what to prepare a network for. They are what the apps are built to handle, not a reading from your phone, and a real call can use less, especially when the connection is weak and the app lowers quality. Use them as a ceiling for planning. Apple and WhatsApp publish no equivalent, which is why the last sections are about measuring.

Zoom's figures, converted to an hour

• 1:1 call, high-quality video, 600 kbps up and down: about 540 MB per hour in total.
• 1:1 call, 720p HD, 1.2 Mbps up and down: about 1.1 GB per hour.
• 1:1 or group call, 1080p HD, 3.8 Mbps up and 3.0 Mbps down: about 3 GB per hour.
• Group call, high-quality video, 1.0 Mbps up and 600 kbps down: about 720 MB per hour.
• Audio only, 60 to 80 kbps: roughly 27 to 36 MB per hour for that stream.

The bandwidths are from Zoom's system requirements page; the hourly totals are the arithmetic from the previous section. Zoom also lists 2.0 Mbps for receiving gallery view with 25 people, so staring at a grid of faces in a big meeting costs far more than a one-to-one chat. Screen sharing without a video thumbnail is listed at 50 to 75 kbps, which is light.

Google Meet, and what it does on mobile data

For individuals and small organisations, Google gives up to 1.7 Mbps each way for 720p video and up to 3.6 Mbps each way for 1080p, which at full rate for an hour comes to about 1.5 GB and 3.2 GB. Group meetings can take up to 4.0 Mbps coming in, and audio only is 100 kbps each way, about 90 MB an hour in total. Google adds that a still screen share uses no more bandwidth once it has loaded.

On a phone, Meet's help says that when you cannot connect to Wi-Fi, it automatically lowers your connections to 1 Mbps. The app also has a Limit data usage switch, under Menu, Settings, then General, or Meeting settings on personal accounts. Google notes one detail worth knowing: even on Wi-Fi, Meet uses a small amount of mobile data as a backup in case the Wi-Fi drops, unless you turn mobile data off.

FaceTime: no figure, but two settings that matter

Apple does not publish how much data a FaceTime call uses. What it does document is how the iPhone's data modes affect it. In Low Data Mode, Apple says FaceTime optimises video bitrate for lower bandwidth. At the other end, Allow More Data on 5G enables higher-quality FaceTime, among other heavier features. On a travel line, Low Data Mode is the setting that fits.

If you would rather keep FaceTime off mobile data entirely, go to Settings, Cellular, and switch off FaceTime in the list of apps; Apple says an app with cellular data off uses only Wi-Fi. FaceTime calls go over whichever line carries data, so with a travel eSIM they come out of the travel plan while your number stays the same, as the iMessage and FaceTime guide explains.

Measure one call before the trip

Since none of the published figures is a meter reading, the reliable number comes from your phone. At home, reset the mobile data statistics, switch off Wi-Fi and make a ten-minute video call with the app you will use abroad. Then open the per-app list in the mobile data settings and read the figure. Multiply by six for an hour and you have a number for your phone, your app and your habits.

Do it once with the camera on and once with it off, and the difference tells you how much the video is costing. For WhatsApp, the app keeps its own count of call data under Storage and data, Network usage; the WhatsApp call guide has the details. This guide shows where the phone's counter is on iPhone and Android.

Making a call lighter on a data plan

Camera off is the big one: in Zoom's figures audio needs 60 to 80 kbps against 600 kbps for high-quality video. Speaker view instead of a grid helps in group calls, and a still shared document costs little once it has loaded. Low Data Mode on iPhone, or Limit data usage in Meet, keeps the video modest without you thinking about it.

The work calls are the ones that add up, especially from a laptop on your phone's hotspot, where a call on a big screen is easy to leave in HD. If the trip involves meetings, size the plan for them; the business travel guide and the hotspot guide cover that case. A travel eSIM can be topped up without reinstalling it, so a week of unexpected calls does not leave you stuck.