Bitrate to File Size Calculator
Video/audio bitrate (kilobits, megabits, or gigabits per second)
Total duration of the media file
Number of audio tracks (default: 1)
File Size Calculation
Formula: File Size = (Bitrate × Duration × Audio Tracks) ÷ 8 ÷ 1024 ÷ 1024
Enter bitrate and duration to see file size calculation
Common Bitrate to File Size Examples
| Media Type | Bitrate | Duration | File Size | Storage Impact |
|---|---|---|---|---|
| YouTube 480p | 1,000 kbps | 10 minutes | 73.2 MB | ~70 smartphone photos |
| Netflix HD | 5,000 kbps | 30 minutes | 1.07 GB | ~250 MP3 songs |
| 4K Blu-ray | 50,000 kbps | 2 hours | 42.9 GB | ~8 DVDs |
| MP3 Music | 128 kbps | 4 minutes | 3.75 MB | ~4 high-res photos |
| Podcast (HQ) | 192 kbps | 60 minutes | 84.4 MB | ~80 smartphone photos |
How Bitrate to File Size Calculation Works
Calculating file size from bitrate is essential for anyone working with digital media, whether you’re uploading videos to YouTube, planning storage for a video project, or trying to estimate download times. The calculation is straightforward once you understand the basic formula.
Key Concept: Bitrate measures data per second (usually kilobits per second). File size measures total data stored (megabytes or gigabytes). To convert between them, you multiply bitrate by duration, then convert from bits to bytes (divide by 8), then from bytes to megabytes or gigabytes.
The Core Formula
The fundamental calculation for estimating file size from bitrate is:
Breaking it down step by step:
- Bitrate × Duration: Gives total bits (bitrate is bits per second)
- ÷ 8: Converts bits to bytes (8 bits = 1 byte)
- ÷ 1024 ÷ 1024: Converts bytes to megabytes (1 MB = 1,048,576 bytes)
- × Audio Tracks: Multiplies by number of simultaneous audio streams
Quick Estimate: For rough calculations, use this shortcut: File Size (MB) ≈ Bitrate (kbps) × Duration (minutes) ÷ 14. Audio typically adds 10-20% to video file size, depending on quality.
Understanding Bitrate and Quality
Video Bitrate Standards
Different platforms and formats use specific bitrate ranges for optimal quality and file size balance:
| Quality Level | Resolution | Typical Bitrate | 1 Hour File Size | Common Use |
|---|---|---|---|---|
| Low Quality | 480p (SD) | 500-1,000 kbps | 225-450 MB | Mobile viewing, old videos |
| Standard Quality | 720p (HD) | 1,500-4,000 kbps | 675 MB – 1.8 GB | YouTube, streaming services |
| High Quality | 1080p (Full HD) | 4,000-8,000 kbps | 1.8 – 3.6 GB | Blu-ray, premium streaming |
| Ultra HD | 4K (2160p) | 15,000-50,000 kbps | 6.8 – 22.5 GB | 4K streaming, professional video |
| Raw/ProRes | 4K+ | 100,000+ kbps | 45+ GB | Film production, raw footage |
Audio Bitrate Standards
Audio bitrates are much lower than video but significantly impact overall file size, especially for music and podcasts:
| Audio Format | Typical Bitrate | 1 Minute File Size | Quality Level |
|---|---|---|---|
| Telephone Quality | 8-16 kbps | 0.06-0.12 MB | Low (voice only) |
| Podcast/Radio | 64-128 kbps | 0.48-0.96 MB | Standard (spoken word) |
| MP3 Music | 128-320 kbps | 0.96-2.4 MB | Good to Excellent |
| CD Quality | 1,411 kbps | 10.6 MB | Lossless (CDDA) |
| Hi-Res Audio | 2,000-9,216 kbps | 15-69 MB | Studio Master Quality |
Important: Modern codecs like H.265 (HEVC), VP9, and AV1 can provide similar quality at half the bitrate of older codecs like H.264. Always consider the codec when estimating file sizes.
Practical Applications and Use Cases
YouTube and Social Media Uploads
When uploading to YouTube, Instagram, or TikTok, you need to estimate file sizes to plan upload times and avoid storage limits. A 10-minute 1080p video at 5,000 kbps creates approximately a 366 MB file. At average home internet speeds (10 Mbps upload), this would take about 5 minutes to upload.
Video Production and Editing
Filmmakers and video editors use bitrate calculations to estimate storage needs for projects. A documentary with 20 hours of 4K footage at 50 Mbps requires approximately 450 GB of storage. Adding proxies, audio, and project files can easily double this requirement.
Streaming Service Planning
Streaming platforms calculate bandwidth costs based on bitrate. A service with 1 million subscribers watching 2 hours daily at 5 Mbps consumes approximately 4.5 petabytes of data transfer per month. This directly impacts hosting costs and infrastructure requirements.
Personal Storage Management
Home users recording family videos, video calls, or security footage can estimate how much storage they need. A home security camera recording 24/7 at 1,000 kbps generates approximately 10.5 GB per day, or 315 GB per month.
Frequently Asked Questions
Why is my actual file size different from the calculated size?
Several factors cause discrepancies: Variable bitrate (VBR) encoding uses less data for simple scenes and more for complex ones. Container overhead (MP4, MKV, AVI) adds small amounts of metadata. Audio tracks, subtitles, and chapters increase size. Compression artifacts and encoding efficiency vary between software.
What’s the difference between kbps and Mbps?
kbps means kilobits per second (1,000 bits per second). Mbps means megabits per second (1,000,000 bits per second). 1 Mbps = 1,000 kbps. Video bitrates are typically measured in kbps for SD/HD and Mbps for 4K and above. Always check your units when calculating.
How much does audio contribute to file size?
For video files, audio typically adds 5-20% to the total file size depending on quality. A 128 kbps audio track adds about 9.4 MB per hour. Multiple audio tracks (different languages) multiply this accordingly. For music files, audio is 100% of the file size.
What bitrate should I use for my project?
For online video: 2,500-5,000 kbps for 1080p, 5,000-8,000 kbps for 1440p, 8,000-16,000 kbps for 4K. For archival/master files: Use the highest your storage can handle. For distribution: Follow platform guidelines (YouTube, Vimeo, etc.). Always consider your audience’s internet speeds.
Common Mistakes to Avoid
Mistake 1: Confusing bits and bytes. Internet speeds are in Mbps (megabits per second), while file sizes are in MB (megabytes). 8 megabits = 1 megabyte. A 100 MB file on a 100 Mbps connection takes 8 seconds, not 1 second.
Mistake 2: Forgetting about audio. Video file size calculations must include audio tracks. A 5,000 kbps video with 256 kbps audio actually has 5,256 kbps total bitrate, adding about 5% to file size.
Mistake 3: Assuming constant bitrate. Most modern encoding uses variable bitrate (VBR), which adjusts based on scene complexity. Simple scenes use less data, complex scenes use more. Average bitrate gives an estimate, not an exact file size.
Practical Examples and Scenarios
Example 1: YouTube Video Upload
You’re creating a 15-minute gaming tutorial at 1080p 60fps. Recommended bitrate: 8,000 kbps. Calculation: 8,000 kbps × 900 seconds (15 minutes) = 7,200,000 kilobits. Convert to MB: ÷ 8 ÷ 1024 ÷ 1024 = 0.857 MB. Estimated file size: 857 MB. With 256 kbps audio: add 42 MB ≈ 900 MB total.
Example 2: Video Conference Recording
Recording a 1-hour team meeting at 720p. Typical bitrate: 1,500 kbps. Calculation: 1,500 × 3,600 seconds = 5,400,000 kilobits. Convert to MB: ÷ 8 ÷ 1024 ÷ 1024 = 0.643 MB. Estimated file size: 643 MB. With voice audio at 64 kbps: add 28 MB ≈ 671 MB total.
Example 3: Music Album Storage
A 12-track album, each song 4 minutes at 320 kbps MP3. Per song: 320 × 240 seconds = 76,800 kilobits. Convert to MB: ÷ 8 ÷ 1024 ÷ 1024 = 0.00915 MB ≈ 9.15 MB. Whole album: 9.15 × 12 = 109.8 MB. In FLAC (lossless, ~1,000 kbps): approximately 343 MB.
Pro Tip: When planning storage for video projects, add 20-30% overhead for project files, cache, renders, and backups. A calculated 100 GB project might actually need 130 GB of storage when all elements are considered.
Technical Considerations
Codec Efficiency
Modern codecs provide better compression than older ones at the same quality level. H.265 (HEVC) can reduce file sizes by 50% compared to H.264 at similar quality. AV1 offers another 30% improvement over H.265. However, more efficient codecs require more processing power to encode and decode.
Frame Rate Impact
Higher frame rates (60fps vs 30fps) typically require 1.5-2x the bitrate for similar quality, as there are twice as many frames to encode. However, efficient codecs and motion compensation can reduce this impact for content with little motion.
Color Depth and HDR
10-bit color and HDR (High Dynamic Range) content requires 25-50% more bitrate than 8-bit SDR content at the same resolution. The additional color information and brightness range need more data to maintain quality.
Why This Calculator Is Essential
Our Bitrate to File Size Calculator provides instant, accurate estimations with several key advantages:
- Real-time calculation: Updates instantly as you adjust any parameter
- Flexible units: Works with kbps, Mbps, and Gbps seamlessly
- Multiple outputs: Shows results in MB, GB, and TB for easy comparison
- Audio track support: Accounts for multiple audio streams
- Practical presets: Quick settings for common scenarios
- Educational: Shows the calculation formula and steps
- Mobile optimized: Works perfectly on all devices
- No installation needed: Runs directly in your browser
- Completely free: No signup, no fees, no limitations
- Privacy focused: We don’t store or track your calculations
Whether you’re a student learning about digital media, a content creator planning uploads, a professional estimating storage needs, or just curious about file sizes, this tool provides reliable estimates instantly. The clear interface and immediate feedback make it perfect for anyone who needs to understand the relationship between bitrate, duration, and file size without unnecessary complexity.