How the calculator gets its number (worked example)
The calculator starts from a base bitrate for each resolution (360p 500, 480p 1,200, 720p 3,000, 1080p 5,000, 1440p 9,000, 4K 20,000 kbps). It multiplies that by 1.4 for 60 fps or 0.85 for 24 fps, then by a use-case factor: Web Streaming 0.9, Upload 1.0, Archival 1.5, Social 0.7. These factors are our own rule of thumb, not an official standard. Example: 1080p, 60 fps, Web Streaming:
5,000 kbps × 1.4 (60 fps) × 0.9 (web) = 6,300 kbps ≈ 6.3 Mbps
To turn a bitrate into a file size, multiply by the duration and divide by 8. At 6,300 kbps, 10 minutes (600 s) of video is 6,300 × 600 ÷ 8 ÷ 1000 ≈ 473 MB, before audio.
YouTube's recommended upload bitrates (SDR)
If you are uploading to YouTube, use YouTube's own figures rather than ours. The table below is copied from YouTube Help: recommended upload encoding settings (checked 24 October 2026). The same page recommends 384 kbps for stereo audio.
| Resolution | 24, 25, 30 fps | 48, 50, 60 fps |
|---|---|---|
| 360p | 1 Mbps | 1.5 Mbps |
| 480p | 2.5 Mbps | 4 Mbps |
| 720p | 5 Mbps | 7.5 Mbps |
| 1080p | 8 Mbps | 12 Mbps |
| 1440p (2K) | 16 Mbps | 24 Mbps |
| 2160p (4K) | 35–45 Mbps | 53–68 Mbps |
Encoding at a target bitrate with FFmpeg
ffmpeg -i input.mp4 -c:v libx264 -b:v 6300k -maxrate 6300k -bufsize 12600k -c:a aac -b:a 192k output.mp4
-b:v sets the average video bitrate, and -maxrate with -bufsize keeps peaks in check. We ran this exact command on a 20-second 1080p test clip with FFmpeg 8.1.2 (24 October 2026). Across two runs, ffprobe measured the video at about 6,373–6,375 kbps and the audio at about 192 kbps. The files were 16,437,174 and 16,442,006 bytes. The formula predicts (6,300 + 192) × 20 ÷ 8 × 1000 = 16,230,000 bytes, so the real files were about 1.3% larger. The command box above the table generates this same FFmpeg target-bitrate command.
Understanding Bitrate
Bitrate is the amount of data processed per second in a video stream. Higher bitrates = better quality but larger files. The right bitrate depends on your resolution, frame rate, and where the content will be watched.
- Audio Extractor Guide: Audio Extractor Guide
- YouTube Compression Guide: YouTube Compression Guide
- CBR (Constant Bitrate): keeps the data rate steady, which is why live-streaming services usually ask for it. Simple scenes get the same bitrate as complex ones.
- VBR (Variable Bitrate): spends more bits on complex scenes and fewer on simple ones around an average. YouTube's upload guidance says no bitrate limit is required for uploads and its figures are for reference.
- Two-pass encoding: the encoder analyses the video first, then encodes, so the result lands closer to the target average bitrate (and therefore the target file size). It takes about twice as long.
- YouTube upload guide: Complete YouTube Upload & SEO Guide
- Pick the right dimensions: Aspect Ratio & Resolution Calculator
- Need video titles? YouTube Title Generator
- Need YouTube keywords? YouTube Tags Generator
- Write your description: Description Generator with timestamps & hashtags
- Compress your video: YouTube Video Compressor
- Check your SEO score: YouTube SEO Checker
- OBS streaming bitrate: Trimpx OBS Settings Calculator
- Video trimming workflow: How to Trim Video with Shotcut
- Estimate output file sizes: File Size Calculator
- Copy-ready encoding commands: Browse FFmpeg Presets
Need a file size from a bitrate? Use the Video File Size Calculator.