How many viewers can one server carry?
6 October 2026 · UndaMedia
It's the first question in almost every conversation we have: "How many people can watch?" The answer is less about the server than people expect, and more about one number on the hosting plan: the upload speed.
Every viewer gets their own copy
On the internet, a server sends each viewer their own copy of the stream. A 3 Mb/s stream watched by 100 people means 300 Mb/s leaving the server. So the sum is simple:
viewers ≈ upload speed × 0.8 ÷ stream bitrate
The 0.8 keeps 20% spare, because connections are never perfectly steady.
| Server upload | Viewers at 3 Mb/s | Viewers at 5 Mb/s |
|---|---|---|
| 100 Mbit/s | about 25 | about 15 |
| 1 Gbit/s | about 250 | about 150 |
| 10 Gbit/s | about 2,500 | about 1,500 |
The processor is rarely the limit
Sending a stream on is copying, not converting. On a test machine, Unda served 200 simulated viewers of a 1080p stream at 5 Mb/s, about 1 Gb/s in total, using roughly a quarter of one processor core, with no freezes.
A more powerful server on the same connection does not serve more viewers. Processor power matters for the work that converts video: making several qualities, 24/7 channels and backup encoders. That is a separate sum; see how far one server goes.
What changes the sum
- Restreaming uses the same upload. Each destination, such as YouTube or Facebook, costs as much as one viewer at its bitrate. Once there, those platforms serve their own viewers.
- Adaptive bitrate lets more people fit. Viewers on slow connections take a smaller quality, so the average bitrate per viewer drops. It also keeps those viewers watching instead of buffering.
- The bitrate itself. 720p at 2.5 Mb/s looks good on most phones and laptops and serves twice as many viewers as 1080p at 5 Mb/s.
Check the monthly allowance too
Many hosting plans advertise a fast port but include a monthly transfer allowance. Streaming uses it quickly: one viewer watching a 3 Mb/s stream for two hours receives about 2.7 GB. A two-hour service watched by 100 people is about 270 GB. Weekly, that is over a terabyte a month. Check the plan's allowance and what it charges beyond it.
When the uplink is full
When more people come than the upload can carry, everyone's picture suffers together. Unda lets you set a cap on outgoing bandwidth instead: once it is reached, new viewers are told to try later while everyone already watching keeps a smooth picture. With a cap set, the dashboard shows how much room is left as "room for about N more viewers", worked out from the actual traffic.
Bigger than one server
For audiences beyond what one connection can carry, the usual answers are a content delivery network (CDN) in front of the server, or restreaming the big public part of the audience to YouTube or Facebook while your own players serve members or paying viewers.
If you're planning an event and want a second opinion on the numbers, send us the details.
← All articles · Related: Adaptive bitrate · Restreaming