Enter a video bitrate and duration to find the raw file size before any container overhead. Useful for estimating storage requirements for recordings, exports, and archives.
Inputs
Video Parameters
The number of bits encoded per second. Higher bitrates preserve more visual detail but produce larger files. Standard HD streaming typically uses 4–8 Mbps; professional production can exceed 100 Mbps.
The total playback length of the video. Longer videos grow the file size in direct proportion to the duration.
Results
Enter a value to see results.
Estimated File Size
The uncompressed data size of the video stream: ... of storage for 60 min of footage at 8 Mbps. This is the raw bitstream size; actual container files (MP4, MKV) add a small overhead.
Video Bitrate and File Size
A video file is a sequence of compressed frames delivered at a fixed bitrate. Once you know the bitrate and the running time, the raw data volume follows from a single formula.
The formula
F=8R×t
where is the bitrate (bits/s), is the duration (s), and is the file size (bytes). The division by 8 converts bits to bytes, since one byte holds eight bits.
Worked example. A one-hour 4K streaming master encoded at 40 Mbps:
F=840,000,000 bps×3,600 s=18,000,000,000 B=18 GB
Common bitrate values by use case
Use case
Typical bitrate
1080p streaming (H.264)
4–8 Mbps
1080p Blu-ray (H.265)
15–40 Mbps
4K streaming (H.265)
15–25 Mbps
Broadcast HD (XAVC)
50–100 Mbps
Cinema RAW (uncompressed 4K)
3–12 Gbps
Container overhead
The formula gives you the size of the raw encoded video stream. Real files (MP4, MKV, MOV) wrap that stream inside a container, which adds a small metadata header — typically well under 1 % of the total size. For estimates and storage budgets the container overhead is negligible; for precise bit-exact comparisons, measure the actual file.
Variable bitrate (VBR)
Many codecs use variable bitrate encoding: simple scenes get fewer bits, complex ones get more. The bitrate you enter into this calculator should be the average bitrate if you are using VBR, because the file size integrates the bit flow over the whole duration. Encoding software often reports an average bitrate in its output log.
Relationship to download time
File size connects directly to download and upload time. If you know the file size and your network speed, use the Download Time Calculator to find how long the transfer takes.
Storage planning
When planning a recording session or a video archive, multiply the per-file estimate by the number of clips. A two-hour film at 100 Mbps needs roughly 90 GB; ten such films need 900 GB. Allowing a 20 % buffer for takes, proxies, and project files is common practice.
Frequently Asked Questions (FAQ)
How does bitrate relate to video resolution?
Resolution sets how many pixels each frame contains; bitrate controls how many bits are allocated to encode those pixels. A high-resolution video at a low bitrate will look blocky because there are not enough bits to represent each pixel accurately. As a rough guide, 1080p at 30 fps typically needs 5–8 Mbps for streaming and 50–100 Mbps for broadcast-quality production.
Why divide the bitrate by 8 to get file size?
Bitrate is measured in bits per second, but file sizes are measured in bytes, and one byte contains eight bits. To convert the total bit count to bytes, divide by 8. For example, a 10 Mbps stream running for one hour produces 10,000,000 × 3,600 = 36,000,000,000 bits = 4.5 GB.
Does the result apply to streaming or downloaded files?
This calculator computes the raw data volume of the video stream itself, which is the same whether the file is streamed or stored locally. What differs is delivery: streaming services add adaptive-bitrate overhead and may re-encode your upload, while a locally stored file is a one-to-one match with the bit count shown here.
Why does a compressed video file appear smaller than this estimate?
The file size shown is the size of the encoded video stream at the stated bitrate — the bitrate already accounts for the codec's compression. H.264 and H.265 typically produce a file very close to (bitrate × duration ÷ 8), unless variable bitrate (VBR) encoding is used, where the actual file can be smaller or larger than a constant-bitrate (CBR) estimate.
