Bitrate Calculator
Use this tool to calculate either required bitrate (from target file size + duration) or estimated file size (from bitrate + duration).
What Is Bitrate?
Bitrate is the amount of data used per second in audio or video. It is usually measured in kbps (kilobits per second) or Mbps (megabits per second). In practical terms, bitrate controls how much information is available to represent your media.
Higher bitrate usually means better quality, but it also means larger files and more bandwidth needed for streaming. Lower bitrate reduces file size and speeds up delivery, but can cause blur, blockiness, and audio artifacts.
Why a Bitrate Calculator Matters
If you upload video to YouTube, stream gameplay, publish a course, or archive recordings, you constantly balance three things:
- Visual and audio quality
- File size and storage cost
- Playback performance on different internet speeds
A bitrate calculator removes guesswork. You can quickly estimate safe settings before exporting, instead of repeatedly encoding and testing.
Formulas Used in This Calculator
1) Required bitrate from file size and duration
Total Bitrate (kbps) = (File Size in bytes × 8) ÷ Duration in seconds ÷ 1000
If audio bitrate is entered, the calculator also estimates:
Video Bitrate (kbps) = Total Bitrate − Audio Bitrate
2) Estimated file size from bitrate and duration
File Size in bytes = (Total Bitrate in bps × Duration in seconds) ÷ 8
Where:
- Total bitrate (kbps) = video bitrate + audio bitrate
- Total bitrate in bps = kbps × 1000
How to Use This Calculator
Find required bitrate
- Select Find required bitrate.
- Enter your video duration.
- Enter target file size and unit (MB, GB, MiB, or GiB).
- Optionally add audio bitrate (for example, 128 kbps).
- Click Calculate.
Estimate file size
- Select Estimate file size.
- Enter duration.
- Enter video and audio bitrate.
- Click Calculate to see output in MB, MiB, GB, and GiB.
Practical Bitrate Ranges (General Guidance)
- 720p @ 30fps: ~2,500 to 5,000 kbps
- 1080p @ 30fps: ~4,000 to 8,000 kbps
- 1080p @ 60fps: ~6,000 to 12,000 kbps
- 1440p @ 60fps: ~12,000 to 24,000 kbps
- 4K @ 30fps: ~20,000 to 45,000 kbps
- Stereo audio (AAC): 128 to 320 kbps
Actual needs vary by codec (H.264, H.265/HEVC, AV1), motion complexity, and compression settings.
CBR vs VBR: Which Should You Use?
CBR (Constant Bitrate)
CBR uses nearly the same bitrate throughout the file. It is easier for live streaming and predictable bandwidth planning.
VBR (Variable Bitrate)
VBR adjusts bitrate by scene complexity. Fast motion receives more data; static shots receive less. This often gives better quality at similar average file size.
Common Mistakes to Avoid
- Using high resolution with very low bitrate, causing soft or blocky output.
- Ignoring audio bitrate when trying to hit strict file-size targets.
- Comparing MB and MiB as if they are identical units.
- Choosing bitrate first without considering frame rate and codec efficiency.
Quick FAQ
Is higher bitrate always better?
Not always. Past a certain point, quality gains are minimal while file size increases significantly.
What unit should I use: MB/GB or MiB/GiB?
Platforms often use decimal units (MB/GB), while system tools may show binary units (MiB/GiB). This calculator supports both to reduce confusion.
Can I use this for audio-only files?
Yes. Enter audio bitrate in the file-size mode and set video bitrate to 0.
Final Takeaway
A good bitrate is not the maximum bitrate. It is the right bitrate for your delivery goal: upload limits, viewer bandwidth, and acceptable quality. Use this calculator to plan exports faster and avoid trial-and-error encoding loops.