Video File Size From Bitrate and Duration: How Much Storage Does Footage Need?
October 21, 2026
Video files are big, and their size is determined mainly by the bitrate, the amount of data used per second of video, and the duration. The formula is simple: file size (MB) = bitrate (megabits per second) × duration (seconds) ÷ 8, since there are 8 bits in a byte. A 10-minute video (600 seconds) encoded at 8 Mbps is 8 × 600 ÷ 8 = 600 MB. At 20 Mbps, the same video is 1,500 MB, or 1.5 GB.
The resolution and frame rate influence the bitrate needed for good quality, but the file size follows directly from the bitrate you choose or that your camera uses.
Skip the math and get your answer instantly:
Open the Weight Converter →Typical Bitrates
Streaming services use adaptive bitrates, and the numbers depend on the codec. Cameras record at much higher bitrates to preserve quality for editing. The values below are typical ranges, and actual settings vary by device and codec (H.264, H.265/HEVC, AV1, ProRes).
Audio adds a small amount: stereo AAC at 128 to 256 kbps adds roughly 1 to 2 MB per minute.
| Use | Typical video bitrate | Size per minute | Size per hour |
|---|---|---|---|
| Web video, 720p | 2.5 to 5 Mbps | 19 to 38 MB | 1.1 to 2.3 GB |
| Streaming 1080p | 5 to 8 Mbps | 38 to 60 MB | 2.3 to 3.6 GB |
| Streaming 4K | 15 to 25 Mbps | 113 to 188 MB | 6.8 to 11 GB |
| Phone 4K recording | 40 to 100 Mbps | 300 to 750 MB | 18 to 45 GB |
| Camera 4K for editing | 100 to 400 Mbps | 750 to 3,000 MB | 45 to 180 GB |
Worked Examples
A 45 Mbps camera recording of 1 hour: 45 × 3,600 ÷ 8 = 20,250 MB, about 20.3 GB. A 90-minute movie streamed at 5 Mbps downloads 5 × 5,400 ÷ 8 = 3,375 MB, about 3.4 GB. A 5-minute product video at 12 Mbps uses 12 × 300 ÷ 8 = 450 MB. If you need to upload a 2 GB video at an upload speed of 20 Mbps, time = 2,000 × 8 ÷ 20 = 800 seconds, about 13 minutes at best; allow 20% extra for overhead.
To plan storage for a shoot, multiply the expected hours by the file size per hour, add backups, and leave room for editing exports. A day of 6 hours at 100 Mbps produces 270 GB.
Choosing the Right Bitrate
Higher bitrates preserve more detail but increase file size and bandwidth needs. Efficient codecs, such as H.265 and AV1, deliver the same quality at about 30% to 50% lower bitrates than H.264, at the cost of more processing power. Motion-heavy content, like sports, needs higher bitrates than static scenes, such as lectures. For uploading to platforms, follow the recommended settings, since they re-encode your upload anyway. Constant bitrate (CBR) gives predictable size; variable bitrate (VBR) varies with the scene and can be more efficient.
Reducing File Size
Lower the resolution or bitrate, use a more efficient codec, trim unnecessary footage, reduce the frame rate (30 fps instead of 60), and compress audio. Check quality after each change. Tools such as HandBrake and FFmpeg make batch compression simple. Keep an original master file if you may need to re-edit later.
Network Planning
To stream a 5 Mbps video smoothly, your connection needs at least that much, plus headroom for other devices. A household with four simultaneous 1080p streams at 5 Mbps each needs 20 Mbps just for video. Data caps matter too: one hour of 1080p streaming uses about 2.3 GB, so a 1 TB monthly cap allows around 430 hours.
Frequently Asked Questions
How do I calculate video file size?
Bitrate in Mbps times duration in seconds divided by 8 gives megabytes.
How big is one hour of 1080p video?
Roughly 2 to 4 GB for streaming-quality bitrates, much more from cameras.
What's the difference between Mbps and MBps?
Mbps is megabits per second. MBps is megabytes per second, 8 times larger.
Which codec gives the smallest files?
Newer codecs such as H.265 and AV1 achieve the same quality at lower bitrates than H.264.
How long to upload a 2 GB file at 20 Mbps?
About 13 minutes at best.