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Video Bitrate Calculator - Estimate File Size & Streaming Bandwidth

Calculate optimal video bitrate and estimate file sizes based on resolution, frame rate, duration, and codec.

Results

Recommended Bitrate (Low)-
Recommended Bitrate (Medium)-
Recommended Bitrate (High)-

Estimated File Size (Low)-
Estimated File Size (Medium)-
Estimated File Size (High)-

Resolution-
Codec-
Duration-

Click "Calculate" to see recommended bitrate and estimated file size.

How It Works

Video bitrate determines how much data is used to represent each second of video. Higher bitrates produce better visual quality but result in larger files and require more bandwidth for streaming. Finding the optimal bitrate means balancing quality against file size and delivery constraints. This calculator uses industry-standard formulas to recommend bitrate ranges based on your video parameters, helping you make informed decisions about encoding settings before committing to a lengthy encode process.

The Bitrate Formula

The fundamental relationship is: Bitrate = Width x Height x Frame Rate x Bits Per Pixel (BPP). The BPP factor varies by codec efficiency and desired quality level. For H.264 at standard quality, a typical BPP value is 0.1, meaning each pixel in each frame uses approximately 0.1 bits. Higher quality targets use BPP values of 0.15-0.2, while lower quality (acceptable for streaming) uses 0.07-0.08. This formula accounts for the fact that higher resolutions and frame rates require proportionally more data to maintain the same perceived quality level.

Codec Efficiency Factors

Different codecs achieve different compression ratios at equivalent visual quality. H.264 (AVC) is the baseline reference codec with universal hardware support across all modern devices and browsers. H.265 (HEVC) achieves approximately 40-50% bitrate reduction compared to H.264 at the same quality, thanks to larger coding tree units (up to 64x64 pixels vs 16x16), improved motion compensation, and better intra-prediction. VP9, developed by Google, offers similar efficiency gains to H.265 and is widely used on YouTube and in WebRTC applications. The calculator applies codec-specific efficiency multipliers: 1.0 for H.264, 0.6 for H.265, and 0.6 for VP9. These multipliers reflect real-world encoding benchmarks and represent average efficiency gains across typical video content.

File Size Estimation

Once the bitrate is determined, file size is calculated as: File Size (MB) = Bitrate (kbps) x Duration (seconds) / 8 / 1024. This gives the video stream size. In practice, the actual file will be slightly larger due to container overhead (MP4 atoms, audio track, metadata), typically adding 5-10% to the total. The calculator shows the video-only estimate; add approximately 128-320 kbps for a stereo audio track depending on the audio codec used (AAC, Opus, or MP3). For longer videos, even small bitrate differences compound into significant file size variations, making accurate estimation essential for storage planning.

Quality Tiers

The calculator provides three quality tiers to cover different use cases. The "Low" tier represents the minimum acceptable quality for streaming, suitable for bandwidth-constrained scenarios such as mobile networks or regions with limited connectivity. The "Medium" tier is the recommended default for most streaming platforms, balancing visual quality and bandwidth consumption for the majority of viewers. The "High" tier targets near-transparent quality suitable for archival, professional production, or premium streaming services where bandwidth is not a concern. Each tier uses different BPP values scaled by the codec efficiency factor to produce accurate recommendations.

All calculations run entirely in your browser using pure JavaScript arithmetic. The formulas execute instantly with no server communication, making this tool completely private and responsive regardless of your internet connection. No video files are processed or uploaded — only the parameters you enter are used in the mathematical computation.

Use Cases

Live Streaming Setup

Determine the right OBS/streaming encoder bitrate for your upload bandwidth and target resolution.

Video Upload Planning

Estimate file sizes before encoding to ensure your video fits within platform upload limits.

Storage Capacity Planning

Calculate how much storage you need for a video library based on resolution and duration targets.

ABR Ladder Design

Plan adaptive bitrate streaming ladders by calculating appropriate bitrates for each resolution tier.

Bandwidth Budgeting

Determine CDN bandwidth costs by calculating data transfer for your expected viewer count and video quality.

Frequently Asked Questions

Video bitrate is calculated based on resolution (total pixels), frame rate, codec efficiency, and desired quality level. The formula multiplies pixels per frame by frames per second, then applies a bits-per-pixel factor that varies by codec and quality target.

CBR (Constant Bitrate) maintains the same bitrate throughout the video, which is predictable for streaming but wastes bandwidth on simple scenes. VBR (Variable Bitrate) adjusts bitrate based on scene complexity, providing better quality-to-size ratio but requiring more buffering consideration.

H.265 (HEVC) uses more advanced compression algorithms including larger coding tree units, improved motion prediction, and better intra-prediction modes. This allows it to achieve similar visual quality at roughly 40-50% lower bitrate compared to H.264, though encoding requires more computational power.

For 1080p at 30fps with H.264, recommended bitrates range from 4,500-6,000 kbps for standard content and 6,000-8,000 kbps for high-motion content. With H.265, you can reduce these values by approximately 40% while maintaining similar quality.

No. This calculator performs all computations locally in your browser using JavaScript. No data is sent to any server. The calculations are purely mathematical formulas that run instantly on your device.

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