Video Bitrate to File Size Calculator
Use this Video Bitrate to File Size Calculator to convert target bitrates and video duration into accurate export file sizes. Plan render times, cloud hosting storage, and client deliveries across H.264, H.265/HEVC, and AV1 before starting your encode.
How Bitrate Dictates Video File Size
A video file size is determined entirely by total bitrate (video stream plus audio stream) multiplied by duration. Display resolution (1080p, 4K) and frame rate (24, 30, 60 fps) control image clarity per frame, but bitrate dictates total data saved to disk each second.
Exporting a 4K master at 10 Mbps and a 720p proxy at 10 Mbps over a 10-minute timeline yields identical file sizes. Higher compression efficiency in newer codecs like H.265/HEVC and AV1 simply allows you to lower the bitrate by 30% to 50% without visible quality loss.
How to Calculate Video File Size from Bitrate
To calculate video file size from bitrate, convert all stream rates into kilobits per second (kbps), multiply by total runtime in seconds, divide by 8,000 (to convert kilobits to Megabytes in decimal SI units), and add container overhead:
File Size (MB) = [((Video kbps + Audio kbps) × Duration (seconds)) / 8,000] × Mux OverheadBitrate to MB per Minute Calculator Quick Check
At 8 Mbps (8,000 kbps video + 192 kbps audio), 1 minute (60 seconds) produces:
(8,192 kbps × 60s) / 8,000 = 61.44 MB per minute (approx. 62.3 MB with MP4 muxing).
How Much Storage Does a 1 Hour 1080p Video Take?
A 1-hour (3,600s) 1080p export encoded in H.264 at 10 Mbps video and 256 kbps audio uses:
(10,256 kbps × 3,600s) / 8,000 = 4,615.2 MB (4.62 GB / 4.30 GiB).
What Bitrate for 4K Video to Stay Under 1GB?
For a 10-minute (600s) 4K export to stay under 1,000 MB (including 192 kbps stereo audio and 1.5% MP4 overhead), your video bitrate must not exceed 13.0 Mbps:
Total kbps = (1,000 MB / 1.015 × 8,000) / 600s = 13,136 kbps - 192 kbps audio = 12,944 kbps (~12.94 Mbps).
*Operating systems like Windows calculate storage in binary Gibibytes (GiB, base 1024), while storage drives, video platforms, and bandwidth providers use decimal Gigabytes (GB, base 1000).*
Container Muxing Overhead (MP4, MOV, MKV, WebM)
Multiplexing video and audio tracks into a container format adds index metadata, moov atoms, timestamps, and packet headers. Factor these real-world margins into your final storage calculations:
| Container Format | Average Overhead | Primary Use Case |
|---|---|---|
| MP4 (MPEG-4 Part 14) | ~1.2% - 1.5% | Web playback, YouTube uploads, social platforms |
| MOV (QuickTime) | ~1.8% - 2.2% | Apple ProRes master delivery, NLE edit exports |
| MKV (Matroska) | ~1.5% - 2.0% | Multi-channel audio, soft subtitles, disc archives |
| WebM | ~1.0% - 1.3% | Native HTML5 browser embedding (VP9/AV1) |
Target Bitrate Guidelines by Resolution & Codec
Recommended starting bitrates for standard frame rates (24-30 fps) and high frame rates (60 fps) across modern codecs:
| Resolution & Frame Rate | H.264 Target | H.265 / AV1 Target | Est. Size (10 Min) |
|---|---|---|---|
| 720p HD (30 fps) | 4 - 6 Mbps | 2 - 3.5 Mbps | ~180 - 450 MB |
| 1080p Full HD (30 fps) | 8 - 12 Mbps | 4 - 6 Mbps | ~300 - 900 MB |
| 1080p Full HD (60 fps) | 12 - 16 Mbps | 6 - 9 Mbps | ~450 - 1.2 GB |
| 1440p (2K QHD) | 16 - 24 Mbps | 10 - 15 Mbps | ~1.2 - 1.8 GB |
| 4K Ultra HD (30 fps) | 35 - 50 Mbps | 18 - 28 Mbps | ~1.4 - 3.8 GB |
| 4K Ultra HD (60 fps) | 55 - 80 Mbps | 28 - 45 Mbps | ~2.1 - 6.0 GB |
Frequently Asked Questions
How do I calculate the file size of a video?
Multiply total stream bitrate in kilobits per second (video stream kbps + audio stream kbps) by duration in seconds, then divide by 8,000 to get decimal Megabytes (MB). Add roughly 1% to 2% to account for MP4 or MOV container overhead.
What is a good bitrate for 1080p video?
For 1080p video at 24 to 30 fps using the H.264 codec, 8 to 10 Mbps provides clean web delivery. For high-motion 60 fps gameplay or sports footage, push to 12 to 15 Mbps. If encoding in H.265/HEVC or AV1, 4 to 6 Mbps provides comparable visual quality at half the storage cost.
How many GB is 1 hour of 4K footage?
At standard web export bitrates of 45 Mbps (H.264), 1 hour of 4K footage takes roughly 20.25 GB. If encoded with efficient codecs like H.265 or AV1 at 25 Mbps, that same 1-hour 4K video consumes approximately 11.25 GB. Uncompressed or ProRes 422 HQ 4K footage will exceed 300 GB per hour.
Does higher bitrate mean bigger file size?
Yes. Bitrate defines data throughput per second. Increasing bitrate directly inflates final file size at an exact linear rate, regardless of resolution or frame rate settings.
Video Bitrate to File Size Estimator
Estimated Total File Size
* Estimated file sizes are calculated based on constant bitrate (CBR) formulas with container multiplexing overhead. Actual file sizes for variable bitrate (VBR) or CRF encodes may vary depending on visual complexity, motion, and codec efficiency.
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