One Hour On Zoom, Measured Three Ways

The Short Answer

How much data does one hour on Zoom actually use? It is the question readers on metered connections ask me most, and the honest answer is a range: about 0.8 to 1.7 GB depending on the call, and the counter you read decides which end of that range you see.

I measured three real calls from my own work three different ways: Zoom's own statistics screen, my router's traffic log, and my provider's app. The same hour of video produced three different numbers every time, with the provider's count running about 10 to 14 percent above the app's own figure. None of the counters was lying. They were counting different things, and the one that matters is the one attached to your bill.

How I Measured One Hour, Three Times

You can take the first of the three readings yourself today, in your next call, in under a minute. While the call runs, open Zoom's Settings and choose Statistics: the screen reports the bandwidth the app is using as it uses it, split by direction, and the overall tab totals what the session has moved.

Note the figure at the end of a call you would call typical, then find the same hour in your router's traffic page or your provider's app and write all three numbers down side by side, the way the table below does. The spread between your three numbers is your household's personal correction factor, and it will serve you better than any figure on this page, mine included.

The three calls came from an ordinary working week at my agency. The first was a one-to-one call with a client, cameras on, an hour of talking through a campaign report. The second was a five-person team call, cameras on, with about twenty minutes of screen sharing while the team reviewed designs. The third was a webinar I only attended: panelists on stage, my camera and microphone off, an hour of watching. For each call I took three readings. Zoom's statistics view reports what the app itself sent and received.

The router log reports everything that crossed my connection from my machine during that hour. The provider's app reports what the network counted against my package. Two ground rules before the numbers. Every GB here is 1,000 MB, the convention the data usage calculator uses; devices that count in 1,024 MB units shift a reading by about 2.4 percent on their own. And Zoom publishes its requirements in megabits per second, so everything converts through one piece of unit math: 1 Mbps held for a full hour moves 450 MB, which is 0.45 GB.

Three Calls, Nine Numbers

The published requirements explain the shape of the table. Zoom asks for 1.2 Mbps each way for a 720p one-to-one call, which caps out near 1.08 GB an hour if both directions ran flat out; my call adapted below that and landed at 0.74 on the app's own count. A 720p group call asks for 2.6 Mbps up and 1.8 Mbps down, a ceiling near 1.98 GB an hour, and my team call with its long screen share settled at 1.52.

Screen sharing on its own is nearly free, which surprised me: Zoom puts sharing without video at 50 to 75 kbps, roughly 0.02 to 0.03 GB an hour. The heavy part of a group call is the grid of faces, not the slides. The webinar deserves its own paragraph, and it gets one below, because it broke the pattern I expected.

One more reading from the same week, for readers on genuinely tight budgets. Zoom's high-quality mode for a one-to-one call, below HD, is listed at 600 kbps each way. Run the conversion and that call costs 1.2 Mbps in total, times 0.45, which is 0.54 GB an hour: a third less than my HD-leaning client call, in exchange for a softer picture that nobody on a work call has ever once complained about.

I keep that figure taped next to the others because it marks the floor. Between the 0.54 GB floor and the 1.68 GB group call sits nearly every working meeting you will ever join, and knowing the floor matters when a student's or a teacher's bundle is measured in single gigabytes.

That result annoyed me at first. The webinar I only watched had cost more than the call I led, and sitting silent with my camera off had still pulled a full HD feed down the line for an hour. Then I thought about what a webinar actually is. A one-to-one call sends one modest video stream and receives one.

A webinar at 1080p pours a full quality stage feed at you continuously, and Zoom's own guidance puts a 1080p attendee feed at roughly 2 to 3 Mbps down, which converts to 0.9 to 1.35 GB an hour. My 1.07 GB sits in that band. Attending quietly is not the same as using little. You are a television audience of one, and the meter runs like one.

Why The Counters Disagree

A word about what these measurements are and are not. Streaming and calling rates are adaptive estimates, not fixed prices: Zoom raises and lowers its bitrate with the state of your connection, so the same meeting held on a struggling line will measure lower and look worse, and the same meeting on a clean line will measure closer to the published ceiling.

My three calls ran on a healthy connection in the same week, which is why they sit near the top of their ranges. Treat the figures as an honest snapshot of one setup, repeat the measurement on your own line if your budget is tight, and expect your numbers to land a little under mine on a slow connection and a little over them if your provider counts more aggressively than mine.

Three gaps, three ordinary causes. The router count sits above the app count because the router cannot tell Zoom's packets from my mail fetching, a design file syncing, or the operating system checking for updates in the background of the same hour. Everything my machine moved is in the router's number.

The provider count sits above both because the network counts at its own layer: protocol overhead, retransmitted packets on an imperfect line, and both directions of traffic, uploads included. Providers also tend to round sessions in their own favor at the edges. Add the 1,000 versus 1,024 MB convention and a 10 to 14 percent spread stops looking like an error and starts looking like three honest instruments pointed at slightly different things.

Three honest counters gave me three honest numbers. The bill only ever believes one of them.

Which Number To Budget With

Budget with the provider's figure, always, because that is the counter that empties your package. The use case I had in mind while measuring was a teacher on a metered connection planning a week of classes: eight one-to-one hours and four group hours. At the provider's rates that week costs 8 times 0.83 plus 4 times 1.68, which is 6.64 plus 6.72, a total of 13.36 GB a week and about 57 GB across a 30 day month of teaching.

Run the same week at the app's own figures and you get a plan that is short by roughly a tenth, which is exactly the shortfall that ambushes people in week four. Two habits protect the budget further. Call settings move these numbers more than call length does, and I priced the toggles one by one in Video Call Settings And Their Data Price Tag.

And a week of calls is only one line in a working month; My Work From Home Data Budget shows how the calls, the sync and the browsing add up when client season arrives. Measure your own three counters once, note the spread, and plan with the rudest number of the three. It is the only one that sends invoices.