Video File Size Estimator

Estimate video file size based on bitrate, duration, and resolution. Calculate how much storage a recording or export will use before you start.

About the Video File Size Estimator

Before recording gameplay or exporting an edited video, it helps to know how large the file will be. File size depends primarily on bitrate and duration — a 10-minute recording at 50 Mbps is roughly 3.7 GB, while the same recording at 8 Mbps is only 600 MB.

This calculator estimates file size based on your bitrate setting and video duration. Use it to plan storage for recordings, estimate upload times, and compare different quality settings. Higher bitrate means better quality but larger files and longer upload times.

Understanding file size math is fundamental for content creators managing recording sessions, disk space, and upload schedules. It's simple arithmetic but easy to misjudge when planning storage needs.

Gamers, streamers, and content creators benefit from precise video file size data when optimizing their setup, planning purchases, or maximizing performance and value. Bookmark this tool and return whenever your hardware, games, or streaming requirements change.

Why Use This Video File Size Estimator?

Knowing file sizes in advance prevents full disk warnings during recording, helps plan upload schedules, and guides bitrate/quality decisions based on your available storage and bandwidth. Instant results let you compare different configurations and scenarios quickly, helping you get the best performance and value from your gaming budget. No account or download is required, and calculations happen instantly in your browser so you can test ideas on the fly. No account or download is required, and calculations happen instantly in your browser so you can test ideas on the fly.

How to Use This Calculator

  1. Enter the video bitrate in Mbps.
  2. Enter the video duration in minutes.
  3. Review the estimated file size in MB and GB.
  4. Compare different bitrate settings to find your optimal tradeoff.

Formula

file_size_MB = bitrate_Mbps × duration_seconds / 8 file_size_GB = file_size_MB / 1024 Where: bitrate_Mbps = video bitrate in megabits per second duration_seconds = video length in seconds 8 = bits to bytes conversion

Example Calculation

Result: 4.39 GB

30 minutes at 20 Mbps: 20 × 1800 / 8 = 4,500 MB = 4.39 GB. This is a typical file size for a high-quality local recording of a 30-minute gaming session.

Tips & Best Practices

Bitrate and Quality Relationship

Bitrate is the most direct control over video quality and file size. For gaming content, fast-motion scenes (FPS, racing) need higher bitrate than slow scenes (strategy, visual novels). Variable bitrate encoding intelligently allocates more bits to complex scenes.

Storage Planning for Creators

A daily recording habit at 20 Mbps for 2 hours produces about 18 GB/day or 540 GB/month. Annual storage needs exceed 6 TB. Plan your storage strategy: active SSD for current projects, archive HDD for completed work, cloud backup for critical content.

Codec Evolution

The shift from H.264 to H.265 and AV1 means smaller files at equivalent quality. As GPU encoding for new codecs improves, switching codecs becomes free performance. Keep your recording software updated to benefit from codec improvements.

Frequently Asked Questions

How much space does a 1-hour recording take?

At 8 Mbps (stream quality): ~3.5 GB. At 20 Mbps (good local quality): ~8.8 GB. At 50 Mbps (high local quality): ~22 GB. At lossless: 100+ GB. Choose based on your storage capacity and quality needs.

Does resolution affect file size directly?

Resolution affects file size indirectly through bitrate. Higher resolution requires higher bitrate for equivalent quality. A 1080p video at 8 Mbps and a 4K video at 8 Mbps are the same file size, but the 4K video looks worse because the bitrate is spread over more pixels.

What bitrate should I use for recording?

For stream archives: 6-8 Mbps. For editing source: 20-40 Mbps. For archival quality: 40-60 Mbps. Higher bitrate gives your editor more data to work with when color grading and cropping. For content you won't edit, stream-quality bitrate is fine.

Why is my video larger than calculated?

Variable bitrate (VBR) encoding can exceed the target during high-motion scenes. Audio stream adds additional size. Container overhead adds a small amount. For CRF-based encoding, actual bitrate varies by content complexity.

CRF vs CBR — which should I use for recording?

CRF (Constant Rate Factor) produces better quality per file size. CBR (Constant Bit Rate) produces predictable file sizes. For local recording, CRF 18-23 is recommended. For streaming, CBR is required by most platforms.

How does codec affect file size?

H.265 (HEVC) produces 30-50% smaller files than H.264 at equivalent quality. AV1 is 20-30% smaller than H.265. However, newer codecs require more CPU/GPU to encode and may not be universally compatible. H.264 remains the safest default.

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