Enter the pixel width and height, frames per second, and video length into the calculator to estimate the uncompressed video file size (assumes 24-bit RGB, 3 bytes per pixel). For most real-world compressed videos (e.g., H.264/H.265), file size is primarily determined by the chosen bitrate and codec settings.
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Video File Size Formula
This calculator estimates the size of uncompressed 24-bit RGB video. That means each pixel uses 3 bytes of color data, and every frame is stored in full. It is most useful for estimating storage needs for raw footage, capture buffers, editing drives, and temporary renders.
\text{File Size (bytes)} = W \cdot H \cdot 3 \cdot FPS \cdot T\text{File Size (GiB)} = \dfrac{W \cdot H \cdot 3 \cdot FPS \cdot T}{1024^3}Variable Definitions
- W = video width in pixels
- H = video height in pixels
- 3 = 3 bytes per pixel for 24-bit RGB color
- FPS = frames per second
- T = total duration in seconds
If you increase any one of these inputs, the file size increases directly. For example, doubling the frame rate doubles the file size, and doubling both width and height increases the total pixels by 4×.
How to Calculate Video File Size
- Find the video resolution in pixels, such as 1920 × 1080 or 3840 × 2160.
- Identify the frame rate, such as 24 fps, 30 fps, or 60 fps.
- Convert the full duration to seconds.
- Multiply width × height × 3 × fps × time to get total bytes.
- Convert bytes into KiB, MiB, GiB, or TiB if needed.
Example
For a 1920 × 1080 video at 30 fps with a duration of 60 seconds:
\text{GiB} = \dfrac{1920 \cdot 1080 \cdot 3 \cdot 30 \cdot 60}{1024^3} \approx 10.43So, one minute of uncompressed 1080p video at 30 fps is approximately 10.43 GiB.
General Formula for Other Bit Depths
The calculator assumes 24-bit RGB, but the same idea can be expanded to other formats by using bits per pixel.
\text{File Size (bytes)} = W \cdot H \cdot FPS \cdot T \cdot \dfrac{\text{Bits Per Pixel}}{8}This matters when working with formats that use alpha channels, higher bit depth, chroma subsampling, or specialized camera codecs. In those cases, the actual file size can be much larger or smaller than the 24-bit RGB estimate.
Uncompressed vs. Compressed Video
This calculator is for uncompressed video. Most exported files such as MP4, MOV, or WebM are compressed, so their size is usually determined more by bitrate than by raw pixel storage.
\text{Compressed Size (bytes)} \approx \dfrac{\text{Total Bitrate (bits/s)} \cdot T}{8}\text{Compressed Size (bytes)} \approx \dfrac{(B_v + B_a) \cdot T}{8}Where Bv is video bitrate and Ba is audio bitrate. This is why two videos with the same resolution and length can have very different final file sizes after export.
Quick Reference for Uncompressed 24-Bit RGB Video
| Resolution | Frame Rate | Approx. MiB / Second | Approx. GiB / Minute |
|---|---|---|---|
| 1280 × 720 | 30 fps | 79.1 | 4.63 |
| 1920 × 1080 | 30 fps | 178.0 | 10.43 |
| 1920 × 1080 | 60 fps | 356.0 | 20.86 |
| 3840 × 2160 | 30 fps | 711.9 | 41.71 |
| 3840 × 2160 | 60 fps | 1423.8 | 83.43 |
What Has the Biggest Effect on File Size?
- Resolution: More pixels per frame means more data in every frame.
- Frame rate: More frames each second means more total frames stored.
- Duration: Longer videos scale file size linearly.
- Color depth: More bits per pixel increases data per frame.
- Compression settings: For exported files, bitrate and codec usually dominate final size.
Practical Notes
- The calculator uses binary storage units, so 1 GiB = 10243 bytes.
- Duration should be converted to seconds internally: 1 minute = 60 seconds, 1 hour = 3600 seconds.
- If a video includes an alpha channel, high bit depth, or a different pixel format, the actual uncompressed size will differ.
- Streaming and delivery formats are typically far smaller than raw RGB because they use temporal and spatial compression.
FAQ
Why is the estimated file size so large?
Because uncompressed video stores every frame directly. Even short clips become very large at high resolutions and frame rates.
Why doesn’t this match my exported MP4 size?
Your exported file is compressed. Compression reduces file size dramatically, so bitrate becomes the more useful estimate for final delivery files.
Does audio matter in this calculator?
This calculator focuses on video image data only. In compressed delivery files, audio adds extra size, but it is usually much smaller than the video stream.
Can I use this for 4K or 8K planning?
Yes. The same formula scales directly to higher resolutions, which makes it useful for estimating drive space, memory requirements, and transfer times.
