Video File Size Calculator
File Size (MB)
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File Size (GB)
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How to Estimate Video File Size
File size equals total bitrate multiplied by duration divided by 8. Formula: File Size (MB) = (Video Mbps + Audio Mbps) x seconds / 8.
Typical bitrates: 720p at 5 Mbps, 1080p at 8 Mbps, 4K at 35 Mbps. H.265 achieves similar quality at roughly half the bitrate of H.264.
Audio adds a consistent amount. Stereo at 192 kbps adds about 1.4 MB per minute.
Frequently Asked Questions
What bitrate for YouTube?
YouTube recommends 8 Mbps for 1080p SDR, 35-45 Mbps for 4K SDR.
How much storage for 1 hour of 4K?
At 35 Mbps, about 15.75 GB. At 100 Mbps (high quality), about 45 GB.
Does frame rate affect file size?
Higher frame rates increase data. Doubling fps at the same per-frame quality roughly doubles file size.
What is CBR vs VBR?
CBR uses fixed bitrate throughout. VBR adapts to scene complexity, generally producing better quality at the same average size.
What is the difference between H.264 and H.265 (HEVC) for file size?
H.265 (HEVC) achieves approximately 25-50% better compression than H.264 at the same visual quality, meaning a 1 GB H.264 file could be 500-750 MB in H.265. However, H.265 encoding is significantly slower and requires more processing power for both encoding and decoding. H.264 remains the most widely compatible codec across devices and platforms. For archival and streaming where bandwidth matters, H.265 or newer codecs like AV1 offer substantial file size savings. YouTube re-encodes all uploads regardless of the source codec.
How much storage do I need for security camera footage?
A single 1080p security camera recording continuously at 4 Mbps uses approximately 42 GB per day or about 1.26 TB per month. At 2 Mbps with motion-activated recording (typically 6-8 hours of actual recording per day), storage drops to approximately 5-7 GB per day. For a 4-camera system with 30 days of retention at medium quality, plan for 2-4 TB of storage. 4K cameras at 8-15 Mbps can require 3-4x more storage than 1080p. Most NVR systems use H.265 compression which reduces these figures by 30-50%.