Streaming Bandwidth Calculator
Work out how much upload speed, peak CDN bandwidth and total data transfer a live stream or video-on-demand library needs.
Upload advice assumes one stream sent to a platform that transcodes for you, with 50% headroom. Egress figures are averages; adaptive bitrate usually makes real totals 10–30% lower.
How this calculator works
Every stream has one number at its heart: the bitrate, measured in megabits per second. Everything else follows from it. Multiply the bitrate by the number of people watching at once and you get the peak bandwidth the delivery network has to push. Multiply by time and divide by eight and you get the amount of data that leaves the servers, in megabytes.
The calculator adds a protocol overhead because nothing travels bare over the internet. HLS and DASH segments sit inside MPEG-TS or fragmented MP4 containers, and those containers travel over HTTP and TCP. Headers, playlist refreshes and occasional retransmissions add a few percent. Eight percent is a fair middle figure for most setups.
Upload speed vs CDN bandwidth
These two numbers get mixed up all the time. Your upload speed is what your encoder needs to send one copy of the stream to YouTube, Twitch, Vimeo or your own media server. It does not grow with your audience. The CDN egress is what the platform sends out to viewers, and that grows with every person who presses play. If you run your own server without a CDN, that egress has to come out of your own connection, which is why self-hosting rarely works beyond a handful of viewers.
For upload we recommend 1.5 times the stream bitrate. Home and office connections fluctuate, and an encoder that runs out of headroom drops frames, which viewers see as stutter. If your encoder sends several renditions itself (for example 1080p, 720p and 480p for an adaptive ladder), add their bitrates together before applying the headroom. For a deeper walkthrough, read our guide on video streaming bandwidth requirements.
Why the real totals are usually lower
Adaptive bitrate streaming lets each viewer's player pick the rendition its connection can handle. Phones on mobile data often settle on 480p or 720p even when a 1080p rendition exists, and many people watch in a small window. That pulls the average bitrate below the top rendition. Viewers also join late and leave early. Use the calculator's result as a ceiling for planning capacity and budgets, then compare it with your platform's analytics after the first event.
Worked example
A webinar at 1080p30 and 5 Mbps, with 1,000 people watching for two hours, needs about 5.4 Gbps of peak egress once overhead is added. Each viewer pulls roughly 4.9 GB, and the event delivers about 4.9 TB in total. The presenter needs only about 7.5 Mbps of upload. If a CDN charges $0.02 per GB, delivery for that event would cost around $97.
Frequently asked questions
How much bandwidth do I need to stream 1080p?
A typical 1080p stream at 30 fps uses about 4.5 to 6 Mbps with H.264. For a live broadcast, plan an upload speed of at least 1.5 times the stream bitrate, so roughly 9 Mbps for a 6 Mbps stream.
Does the number of viewers affect my upload speed?
Not when you use a streaming platform or CDN. You upload one stream and the CDN copies it to every viewer. Viewer count affects CDN egress and cost, not your home or studio upload.
Why add protocol overhead?
HLS and DASH wrap audio and video in containers and send them over HTTP and TCP. Headers, manifests and retransmissions add roughly 5 to 10 percent on top of the encoded bitrate.