How many visitors are online at the same time at an event?

In our experience, around 20 to 40 percent of WiFi users are active at the same time at the busiest moment. At a congress you're at the low end: at the Congres Lokaal Sportbeleid, 190 of roughly 1,000 participants were connected at the peak. At a festival, where everyone shares videos at once, you're at the high end.

How much bandwidth does a livestream need?

Plan for 10 to 15 Mbps of upload for a stable 1080p stream and 40 Mbps or more for 4K. Upload is the scarce direction at an event, so we give a livestream its own priority connection, separate from the audience.

How much bandwidth does a payment terminal need?

Almost none: a transaction is a few kilobytes. What matters is response time. A terminal that waits half a second already feels slow. That is why we put payment traffic on a separate, prioritised network, never among the visitors.

How Much WiFi Does an Event Need?

Short answer: it’s not the number of visitors that determines your network, but the number of devices doing something at the same time, and what they’re doing. If you call us saying “we expect 3,000 people, how many Mbps do we need?”, the first thing you get back is three questions. Here they are, with the figures we measure on our own sites.

Question 1: how many devices are active at the same time?

Connected is not the same as active. A phone in a pocket is on the WiFi but sends nothing. Only when the headliner starts and everyone uploads a video at once do you find out what the network can handle.

In our experience, around 20 to 40 percent of WiFi users are active at the same time at the busiest moment. At the Congres Lokaal Sportbeleid in Bilzen-Hoeselt, 190 devices were connected at the peak for around 1,000 participants. A congress sits at the low end of that range: people listen to speakers and check their email in between. A festival sits at the high end: everyone shares the same moment at the same time.

Also count on more than one device per person: phone, smartwatch, sometimes a tablet or laptop. For the network’s address space they all count; for throughput, one active device per person is usually what matters.

Question 2: what are those devices doing?

A payment terminal, a crew phone on WhatsApp and a 4K livestream each demand something completely different. This is how we calculate:

Payment terminals and scanners: almost no bandwidth, a transaction is a few kilobytes. What matters is response time. A terminal waiting half a second for an answer already feels slow, and the queue at the bar grows. That’s why payment traffic always gets a separate, prioritised network with us.
Visitors on social media: on average half a megabit per active device, with peaks up to 2 Mbps when video is loaded or uploaded.
Crew on WhatsApp and planning apps: negligible, until someone starts a video call. Then 2 to 3 Mbps in both directions.
Livestream: 10 to 15 Mbps of upload for a stable 1080p stream, 40 Mbps or more for 4K. This is the item that’s underestimated most often.
Cameras: 2 to 4 Mbps per camera in 1080p, 8 to 15 Mbps in 4K, continuously, all day.

Two things stand out. First: the processes that bring in money or keep people safe need little bandwidth but absolute reliability. Second: upload is the scarce direction. A festival crowd downloads little and uploads a lot. A 4G/5G connection or a Starlink dish often delivers less upload than promised in practice. That’s why a livestream gets its own connection with us.

Question 3: where are they?

A bar with eight terminals and two hundred waiting visitors in ten square metres is a different problem from two hundred visitors spread across a meadow. WiFi shares the air: the more devices on the same channel in the same zone, the less each one gets.

That’s why we plan for 50 to 100 active devices per access point, depending on what they’re doing. The hundreds of clients in the spec sheets are a ceiling, not a design target. And we’d rather place more access points at lower transmit power, each for its own zone, than a few that try to cover the whole site and interfere with each other.

This is where the floor plan comes in. Where are the bars, the entrance, the food court, the crew area? That’s where the access points go. Not in the middle of the site “for coverage”.

A worked example

A two-day congress, 1,000 participants, one exhibition hall without a fixed internet line. This is how we calculated the Congres Lokaal Sportbeleid:

Active at the same time: 20 percent of 1,000 is 200 devices at the peak. Measured: 190.
What they do: exhibitors with payment systems, registration software and demos; visitors checking email and social media. Count on 1 Mbps per active device on average, with peaks for demos: 200 to 300 Mbps total throughput.
Where: a hall full of stands that dampen the signal. Four to six access points, plus wired connections for exhibitors who don’t want to entrust their till to wireless.
Result: 150 GB of traffic over two days, no outages.

A festival calculates differently: more audience, higher concentration at the bars, heavier upload. But the method is the same. First the simultaneous devices, then the applications, then the locations.

What we deliberately don’t do

We don’t size for “everyone doing everything at once”. That network doesn’t exist and would be unaffordable. We size for the processes that can’t be allowed to fail (payments, scanning, production, security) and give them priority. Public WiFi gets what’s left, and on a well-designed network that’s more than enough.

During the event we measure live how many devices are connected and how much data is flowing, via Stardex. Last summer, more than 1,000 devices were connected to our networks this way. Those measurements are the best input for designing the next event.

What to send us

Want us to size your event correctly? Include the following in your quote request:

the expected number of visitors and crew, and whether public WiFi is needed;
the number of payment points and scanners;
livestreams or video calls, and in what quality;
cameras and sensors;
a floor plan showing the zones where it will get busy.

With those five points, we build a network that works while the site is still empty, and at the moment the headliner starts.