Streaming bandwidth calculator
Enter the stream bitrate, how many people watch and for how long. The calculator gives the upload speed to have with some headroom, the bandwidth a server needs to send the stream to everyone, and the traffic in gigabytes.
Runs in your browser: nothing you enter is sent anywhere.
How to use it
- Enter the total bitrate of the stream in Mbps (video plus audio), as set in your streaming software.
- Enter the number of people watching at the same time and the length of the stream in hours.
- Set a headroom percentage for the upload; 0 shows the bare bitrate.
- Read the upload speed for the streamer, the bandwidth to serve everyone and the data totals.
- upload = bitrate × (1 + headroom ÷ 100)
- serving bandwidth = bitrate × viewers
- GB per viewer per hour = bitrate in Mbps × 3,600 ÷ 8 ÷ 1,000
- total GB = GB per viewer per hour × viewers × hours
GB and TB here are decimal (1 GB = 1,000 MB), as used for bandwidth and hosting bills.
Worked example
A 6 Mbps stream watched by 100 people for 2 hours, with 25 % headroom:
- upload: 6 × 1.25 = 7.5 Mbps;
- to serve everyone directly: 6 × 100 = 600 Mbps (0.6 Gbps);
- per viewer: 6 × 3,600 ÷ 8 = 2,700 MB = 2.7 GB an hour;
- all viewers: 270 GB an hour and 540 GB for the 2 hours.
Tips
- Upload speed tests show a peak; for a stable stream keep the bitrate well under the speed you measure.
- If viewers’ data allowance matters, 2.7 GB an hour at 6 Mbps is a useful number to tell them.
- To size a recording of the stream, use the video file size calculator with the same bitrate.
Frequently asked questions
What upload speed do I need to stream?
At least the stream bitrate, plus room for the speed to dip. With a 6 Mbps stream and 25 % headroom the calculator suggests 7.5 Mbps of steady upload. Measure your upload at the time of day you stream, as home connections vary.
How much data does a stream use per hour?
Bitrate × 3,600 seconds ÷ 8 bits. A 6 Mbps stream is 6 × 3,600 ÷ 8 = 2,700 MB, that is 2.7 GB per hour for the streamer's upload and for each viewer's download.
Why does serving viewers take so much bandwidth?
When you send the video yourself, each viewer receives their own copy, so the outgoing bandwidth is the bitrate times the number of viewers: 100 viewers of a 6 Mbps stream need 600 Mbps. Streaming platforms and CDNs carry this for you; you only upload one copy.
Does this include different quality versions?
No. It assumes everyone watches the bitrate you enter. If a platform offers lower qualities, viewers who pick them use less; enter an average bitrate across viewers for a rough figure.