Video File Size Calculator by Format
Select your video codec, resolution, frame rate, duration and audio settings to estimate the final file size in megabytes and gigabytes. Results update instantly. The calculator covers streaming codecs (H.264, H.265, AV1, VP9), professional production formats (ProRes, DNxHD), broadcast (MPEG-2) and uncompressed video. A storage comparison table shows how many minutes of footage fit on common devices.
How video file size is calculated
Every video file is a bitstream: a series of bits delivered at a certain rate (bitrate) for a certain amount of time (duration). File size in megabytes equals the total bitrate in megabits per second multiplied by the duration in seconds, divided by 8 (since 8 bits = 1 byte). For example, a 5-minute H.264 clip at 5 Mbps with 128 kbps AAC audio has a combined bitrate of 5.128 Mbps. The file size is 5.128 x 300 seconds / 8 = approximately 192 MB. Resolution and frame rate both scale the bitrate: doubling the pixel count (e.g. from 1080p to 4K) roughly doubles the bitrate, and doubling the frame rate (e.g. from 30 fps to 60 fps) does the same. This calculator applies those multipliers on top of a reference bitrate for each codec at 1080p/30fps.
Choosing a codec: streaming vs production vs delivery
Video codecs split into two families with very different goals. Delivery codecs (H.264, H.265, VP9, AV1) prioritize small files at good quality and run on virtually every device. Among them, AV1 and H.265 are the most efficient, achieving the same perceived quality as H.264 at roughly 40-60% of the bitrate. Production codecs (Apple ProRes 422, ProRes 4444, Avid DNxHD) use much higher bitrates, sometimes 50 to 200 times larger than delivery codecs, because they are designed for edit-time performance, colour grading headroom and repeated encode/decode cycles without quality loss. Uncompressed formats preserve every pixel exactly and are used in high-end VFX pipelines, but a single hour of uncompressed 1080p 8-bit video can exceed 500 GB. The right workflow is to capture or edit in a production format and export in a delivery format for final distribution.
Storage and transfer planning
Knowing file size before you shoot or export helps you plan card capacity, drive space and upload time. A typical 1-hour documentary in H.264 at high quality occupies roughly 3.6 GB. The same footage in Apple ProRes 422 at high quality swells to around 66 GB. For upload speed: divide the file size in megabits (MB x 8) by your upload speed in Mbps to get the transfer time in seconds. A 1 GB file (8192 Mb) over a 50 Mbps connection takes approximately 164 seconds (about 2.7 minutes). For card planning, multiply the per-minute size figure by the expected shoot duration, then add a 20% buffer for overhead, metadata and safety margin.
Why these numbers are estimates
Modern codecs use variable bitrate (VBR) encoding: still scenes get fewer bits and action scenes get more. The figures here are based on average or target bitrates for each codec and quality tier. The real file will be smaller for low-motion content (talking heads, screen recordings) and larger for high-motion content (sports, fast pans, dense textures). Container overhead (MP4, MOV, MKV headers, subtitles, chapter markers) adds a small but usually negligible amount. For professional production budgeting, round up by 15-20% to be safe.
Typical bitrates by codec and use case
| Codec | Low (Mbps) | Medium (Mbps) | High (Mbps) | Ultra (Mbps) | Container |
|---|---|---|---|---|---|
| H.264 / AVC | 2 | 5 | 8 | 16 | MP4 / MKV |
| H.265 / HEVC | 1 | 2.5 | 4 | 8 | MP4 / MKV |
| VP9 | 1.5 | 3 | 5 | 10 | WebM / MKV |
| AV1 | 0.8 | 2 | 3.5 | 7 | WebM / MP4 |
| Apple ProRes 422 | 47 | 94 | 147 | 220 | MOV |
| Apple ProRes 4444 | 88 | 165 | 275 | 440 | MOV |
| Avid DNxHD | 36 | 115 | 175 | 220 | MXF / MOV |
| MPEG-2 | 2 | 6 | 9 | 15 | MPG / TS |
| Uncompressed 8-bit | 1244 | 1244 | 1244 | 1244 | AVI / MOV |
| Uncompressed 10-bit | 1556 | 1556 | 1556 | 1556 | AVI / MOV |
Representative target bitrates for 1080p at 30 fps. 4K content multiplies these by approximately 4 and 8K by approximately 16.
Frequently asked questions
What is the formula for video file size?
File size (MB) = (video bitrate in Mbps + audio bitrate in Mbps) x duration in seconds / 8. For example, a 10-minute clip at 5 Mbps video and 0.128 Mbps AAC audio: (5.128 x 600) / 8 = approximately 384 MB. The bitrate itself depends on the codec, resolution, frame rate and quality setting you choose.
How does resolution affect file size?
4K has four times as many pixels as 1080p, so it requires roughly four times the bitrate to maintain the same per-pixel quality. Likewise, 8K has sixteen times the pixels of 1080p. However, more efficient codecs (H.265, AV1) can compress 4K more aggressively than MPEG-2 or H.264, so the relationship is not identical across formats. This calculator scales the bitrate proportionally to pixel count and frame rate.
What is the difference between H.264 and H.265?
Both are delivery codecs, but H.265 (also called HEVC) uses more advanced compression algorithms to achieve the same visual quality at about 40-50% lower bitrate. That means H.265 files are roughly half the size of equivalent H.264 files. The trade-off is that H.265 encoding is more CPU-intensive and hardware support, while now widespread, is less universal than H.264.
Why is ProRes or DNxHD so much larger than H.264?
ProRes and DNxHD are editing codecs designed for post-production, not delivery. They use a light intraframe compression (each frame is compressed independently, similar to a JPEG sequence) rather than the interframe prediction used by H.264 and H.265. This gives editors instant random access to any frame, better quality after colour grading and fewer artifacts from repeated encodes. The cost is file sizes 20 to 100 times larger. Use them on the editing timeline and export to H.264 or H.265 for distribution.
How do I estimate how many hours of footage fit on a memory card?
Divide the card capacity in MB by the per-minute size shown in the results. For example, if your footage uses 150 MB per minute and you have a 256 GB card (262,144 MB), you get 262,144 / 150 = approximately 1748 minutes, or about 29 hours. Always allow a 10-20% buffer for overhead and file system usage.
Does the audio track make a significant difference?
For compressed delivery formats, audio is a small fraction: 128 kbps AAC adds roughly 58 MB per hour, compared to several gigabytes for the video track. For very short clips or low-bitrate web video, audio can be a noticeable percentage. For professional production formats like ProRes, audio is negligible relative to the massive video track. The size breakdown panel shows the exact split for your settings.
What is variable vs constant bitrate, and which does this calculator use?
Constant bitrate (CBR) delivers the same number of bits per second throughout the clip. Variable bitrate (VBR) allocates more bits to complex scenes and fewer to simple ones, achieving better quality at the same average bitrate. This calculator uses average target bitrates that approximate VBR encode, so real results may vary by 10-20% depending on scene complexity. For precise budgeting, encode a representative sample and measure the actual output size.