About this tool
What Is a Facebook Video Size Calculator?
A Facebook video size calculator estimates how large a video file will be at different quality settings based on its duration and Facebook average compression bitrates. This helps you plan storage space and understand data usage before downloading or streaming.
Formula: File Size (MB) = Bitrate (Mbps) × Duration (seconds) ÷ 8
Facebook Video Quality Tiers
| Quality | Resolution | Bitrate | 1 Min Size | 5 Min Size |
|---|---|---|---|---|
| SD (480p) | 854×480 | ~0.7 Mbps | ~5 MB | ~26 MB |
| HD (720p) | 1280×720 | ~1.5 Mbps | ~11 MB | ~56 MB |
| Full HD (1080p) | 1920×1080 | ~3.5 Mbps | ~26 MB | ~131 MB |
Actual sizes vary by ±20% depending on video complexity (static vs action scenes).
Legal Ways to Save Facebook Videos
- Your own videos: Profile → Videos → Click 3 dots → "Download Video"
- Browser method: Change "www" to "mbasic" in the URL, play the video, right-click → "Save Video As"
- Screen recording: Use OBS (desktop) or built-in screen recorder (mobile)
- Always respect copyright: Only download content you own or have explicit permission to use
Practical Usage Examples
Standard Post Video
5 min HD video
Est. size: ~45-68 MBStep-by-Step Instructions
Step 1: Paste URL. Enter the Facebook video URL (optional — used for reference only).
Step 2: Set Duration. Enter the estimated video duration in minutes.
Step 3: Select Quality. Choose SD (480p), HD (720p), or Full HD (1080p).
Step 4: View Estimates. See estimated file size range, technical specs, and bitrate information.
Step 5: Follow Download Guide. Read the legal methods to save Facebook videos you own or have permission to use.
Core Benefits
File Size Estimation: Calculates approximate download size based on Facebook average bitrates for each quality level, helping you plan storage and data usage.
Technical Specifications: Shows resolution, codec (H.264), frame rate, and bitrate for each quality tier.
Legal Download Guide: Provides step-by-step instructions for saving your own videos and public videos through official and browser methods.
Data Usage Planning: Estimate how much mobile data watching or downloading a video will consume at different quality settings.
Frequently Asked Questions
Estimates are based on Facebook average compression bitrates (0.7 Mbps for SD, 1.5 for HD, 3.5 for FHD). Actual sizes vary by about ±20% depending on video complexity. Action scenes compress larger than static talking-head videos.
Facebook uses encrypted streaming with DRM protection, which blocks direct browser-based downloading. Most browser extensions and third-party sites work around this, but official methods (saving your own videos) are the safest approach.
You can legally download your own uploaded content. Downloading others content for personal offline viewing is generally tolerated but technically violates Facebook Terms of Service. Redistributing downloaded content without permission violates copyright law.
HD (720p) offers the best balance of quality and file size. Full HD (1080p) provides sharper detail but uses roughly double the storage. SD (480p) is best for data-saving on mobile or when quality is less important.
SD quality uses about 0.7 MB per minute. HD uses about 1.5 MB per minute. Full HD uses about 3.5 MB per minute. A 10-minute video in HD would use approximately 112 MB of mobile data.
Facebook encodes videos in H.264 (AVC) with AAC audio, typically in MP4 container format. Frame rate is usually 30fps. Facebook re-encodes uploaded videos to multiple quality levels for adaptive streaming.
Facebook Reels use the same video technology as regular posts. The size estimation works the same way — enter the Reel duration and select quality. Reels are typically 15-90 seconds, so file sizes are small (2-15 MB).
On the Facebook app, tap the 3 dots on any video and select "Save Video" to save it within Facebook. For downloading to your phone storage, use the screen recording feature built into iOS and Android.
Facebook serves different quality levels based on your internet connection. The mbasic method typically saves SD quality. For higher quality, use the Facebook app Save feature or screen recording at the quality currently being streamed.
No. All calculations are performed in your browser. Video URLs, durations, and estimates are never transmitted to any server.