Free tool
Live streaming bandwidth calculator
A free bandwidth calculator for live video that estimates your streaming bandwidth and data usage in seconds, no sign-up required.
Estimate the total delivery bandwidth a live stream will consume from your streaming bit rate, expected concurrent viewers, and event duration.
How to calculate streaming bandwidth
Streaming bandwidth = bitrate × concurrent viewers × time. Total viewing minutes are your concurrent viewers multiplied by the event duration in minutes. Enter the total encoded bitrate for video plus audio. The tool converts that rate from kilobits per second (kbps) to kilobytes per second (KB/s), multiplies by 60 to get kilobytes per minute, then multiplies by the total viewing minutes.
The result is shown in gigabytes (GB) and terabytes (TB). One kilobyte is treated as 1024 bytes, so a megabyte is 1024 KB, a gigabyte is 1024 MB, and a terabyte is 1024 GB, the same binary units the original calculator used.
- Total viewing minutes = concurrent viewers × duration (minutes)
- Kilobytes per second (KB/s) = total encoded bitrate (kbps) ÷ 8
- Total GB = total viewing minutes × (KB/s × 60) ÷ 1024 ÷ 1024
- Total TB = total GB ÷ 1024
Bits, bytes, and bandwidth units
Bitrates are measured in bits (kbps, Mbps) while data usage is measured in bytes (MB, GB, TB). One byte is 8 bits, so a 6 Mbps stream moves 0.75 megabytes of video every second. Mixing the two up skews an estimate by a factor of eight, which is the most common error in manual bandwidth math.
Mbps describes a rate: how much data flows per second. GB describes a volume: how much data was delivered in total. An internet plan quotes a rate, while a streaming plan's bandwidth allowance quotes a volume. This calculator takes your rate and turns it into the volume your audience will consume.
- 1 byte = 8 bits, so divide kbps by 8 to get KB/s
- 1 Mbps sustained for one hour delivers about 0.43 GB per viewer
- Bitrates use decimal prefixes (1 Mbps = 1,000 kbps), while the results here use binary units (1 GB = 1024 MB)
What the numbers mean
This is a delivery estimate: it approximates how much player (viewer-side) bandwidth an audience of the size you enter would consume over the whole event at a single bit rate.
Real usage varies with adaptive bitrate ladders, viewers joining and leaving, buffering, and rendition selection. The plan match compares only this estimate with the selected monthly or annual bandwidth allowance. It does not account for stream, storage, feature, or other plan limits.
Upload bandwidth vs delivery bandwidth
Live streaming uses bandwidth in two places. Upload bandwidth carries one copy of your stream from the encoder to the ingest server. Delivery bandwidth carries a copy to every viewer, so it scales with audience size. This calculator estimates delivery, and your upload requirement stays the same whether 10 or 10,000 people watch.
For the upload side, keep your total encoded bitrate below about 70% of your connection's sustained upload speed, and use the bitrate calculator to pick encoder settings. On the delivery side, Castr sends streams to viewers over multiple CDNs (Akamai, Fastly, and CloudFront) and ingests from 40+ locations, so per-viewer delivery never touches your own connection.
How much data does streaming use?
Delivery data usage = stream bitrate × number of viewers × time. A single 1080p viewer at a 6 Mbps (6,000 kbps) bitrate consumes roughly 2.6 GB per hour, so 100 concurrent viewers watching that stream for one hour use about 257 GB.
The per-viewer figures below use typical encoding bitrates for each resolution. Adaptive bitrate delivery lowers the real total: Castr transcodes your stream into multiple renditions, and viewers on slower connections or smaller screens pull less data than your top rendition. Use the calculator above with your real bitrate, audience size, and duration for an estimate specific to your event.
- 480p at ~1.5 Mbps: about 0.6 GB per viewer-hour (64 GB per hour for 100 viewers)
- 720p at ~3 Mbps: about 1.3 GB per viewer-hour (129 GB per hour for 100 viewers)
- 1080p at ~6 Mbps: about 2.6 GB per viewer-hour (257 GB per hour for 100 viewers)
- 1440p at ~9 Mbps: about 3.9 GB per viewer-hour (386 GB per hour for 100 viewers)
- 4K at ~16 Mbps: about 7 GB per viewer-hour (687 GB per hour for 100 viewers)
Frequently asked questions
How much bandwidth does live streaming use?
It depends on your bit rate, audience size, and event length. Multiply your concurrent viewers by the duration in minutes to get total viewing minutes, then multiply by the per-viewer data rate. This calculator does that math for you and reports the total in GB and TB.
How much data does streaming use per hour?
A 1080p stream encoded at 6 Mbps uses about 2.6 GB per viewer per hour. At 720p and 3 Mbps that drops to about 1.3 GB, and 4K at 16 Mbps rises to about 7 GB. Multiply the per-viewer figure by your concurrent audience to get total delivery data.
Does a higher bit rate use more bandwidth?
Yes. Bandwidth scales linearly with bit rate: doubling the streaming bit rate roughly doubles the total data delivered for the same audience and duration.
Is this the same as my encoder upload usage?
No. This estimates viewer-side (delivery) bandwidth for your whole audience. Your encoder's upload is a single stream to the ingest server. Use the bitrate calculator to plan your encoder settings.
How do I calculate live streaming bandwidth?
Multiply your total encoded bitrate by the number of concurrent viewers and the length of the stream. Convert the bitrate from kbps to KB/s (divide by 8), multiply by the total viewing seconds, then convert to GB. The calculator above does this automatically and reports the total in GB and TB.
How much bandwidth do I need to stream 1080p?
A 1080p stream is usually encoded around 4.5 to 6 Mbps. At 6 Mbps each viewer uses roughly 2.6 GB per hour, so estimate delivery bandwidth by multiplying that by your expected concurrent audience and the event length.
How much bandwidth does 4K streaming use?
A 4K live stream is usually encoded at 15 to 25 Mbps. At 16 Mbps each viewer uses about 7 GB per hour, so 100 concurrent 4K viewers consume roughly 687 GB over a one-hour event. Your encoder upload needs the same 15 to 25 Mbps regardless of audience size.
What upload speed do I need to live stream?
Plan for at least 1.5 times your total encoded bitrate. A 6 Mbps 1080p stream needs about 10 Mbps of sustained upload to leave headroom for protocol overhead and network variance. Upload requirements do not grow with your audience, because delivery to viewers runs over Castr's CDNs (Akamai, Fastly, and CloudFront).
What is the difference between bandwidth and data usage?
Bandwidth is a rate measured in bits per second (Mbps), while data usage is a volume measured in bytes (GB or TB). A 6 Mbps stream describes the rate, and the 2.6 GB one viewer consumes per hour describes the volume. Streaming plans meter the volume, which is what this calculator estimates.
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