Video File Size Calculator
Planning a video shoot? Estimate how much storage space you need for 1080p, 4K, or ProRes footage.
Formula:
Size = Bitrate × Duration
Bitrate is the key driver of quality and size.
Estimated File Size
Mathematical Principles
Video file size is a direct function of the data rate (bitrate) and time. Resolution (like 4K) matters only because it forces you to use a higher bitrate to maintain quality.
1. The Formula
File Size = Bitrate × Duration
2. Understanding Bitrate
Bitrate is usually measured in Mbps (Megabits per second).
To get the file size in GB (Gigabytes):
1. Calculate total Megabits: Bitrate (Mbps) × Duration (seconds)
2. Convert to Megabytes: Total Megabits / 8
3. Convert to Gigabytes: Total Megabytes / 1000 (or 1024 for binary GB)
3. Example: 1 Minute of 4K Video
If your camera records 4K at 100 Mbps:
Total Bits = 100 Mbps × 60 seconds = 6,000 Megabits.
Total Bytes = 6,000 / 8 = 750 Megabytes (MB).
Total GB = 0.75 GB.
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Frequently Asked Questions
The main factor is Bitrate (amount of data per second), followed by Duration. Resolution and Frame Rate indirectly affect file size because higher quality usually requires a higher bitrate to look good.
Need Help?
Check out our detailed guide to understand how to use this calculator and the concepts behind it.
Learn about video size calculations