Video File Size Calculator (by format)
Calculate video file size based on duration and format. Estimate storage requirements for different video codecs and resolutions.
How to Use This Calculator
- Enter your video duration in seconds (or convert minutes/hours to seconds).
- Select your video format from the dropdown (H.264, H.265, ProRes, DNxHD, etc.).
- If using "Custom", enter your specific bitrate in Mbps.
- The calculator displays the estimated file size in bytes, KB, MB, or GB.
Video File Size Formula
Video file size is calculated from bitrate and duration:
Example: H.264 1080p at 8 Mbps for 5 minutes (300 seconds): File Size = (8 × 1,000,000 × 300) ÷ 8 = 300,000,000 bytes = 300 MB.
Full Description
Understanding video file sizes is essential for planning storage, estimating upload/download times, and managing bandwidth. File size depends on three main factors: resolution, codec (compression algorithm), and bitrate (data rate). Different formats use different bitrates to achieve similar quality, with newer codecs like H.265 (HEVC) being more efficient than older ones like H.264.
Consumer formats (H.264, H.265) use aggressive compression to minimize file sizes while maintaining good quality. Professional formats (ProRes, DNxHD) use less compression to preserve quality for editing, resulting in much larger files. The trade-off is file size vs. quality and editing flexibility.
This calculator helps you estimate file sizes for different formats and durations. Use it to plan storage needs, estimate transfer times, and understand the trade-offs between different codecs. Remember that actual file sizes may vary based on video content complexity and encoding settings, but these estimates provide a good starting point for planning.
Frequently Asked Questions
How is video file size calculated?
File size = (Bitrate × Duration) ÷ 8. Bitrate is measured in bits per second (bps), so multiply by duration in seconds, then divide by 8 to convert to bytes. For example, 8 Mbps for 5 minutes = (8,000,000 × 300) ÷ 8 = 300 MB.
What bitrate should I use?
Bitrate depends on resolution and codec: H.264 1080p typically uses 5-8 Mbps, 4K uses 25-50 Mbps. H.265 (HEVC) uses about half the bitrate for similar quality. Professional formats (ProRes, DNxHD) use 100-200+ Mbps for editing.
Why do different formats have different file sizes?
Different codecs use different compression algorithms. H.265 is more efficient than H.264, so it uses lower bitrates for the same quality. Professional formats (ProRes, DNxHD) use less compression for editing flexibility, resulting in much larger files.
How accurate are these estimates?
These are estimates based on typical bitrates. Actual file sizes vary based on video content (complex scenes compress less), encoding settings, and variable bitrate (VBR) vs constant bitrate (CBR). VBR files may be smaller than CBR estimates.