Video Tool
Video File Size Estimator
Calculate the estimated output file size of your video before you render it. Input your resolution, codec, bitrate, and duration to get an accurate estimate โ and compare sizes across codecs side by side.
Estimate File Size
Quick Presets
Estimated File Size
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Why Estimate Before You Render?
A 10-minute 4K ProRes file can easily exceed 50GB. A YouTube upload at the same quality in H.265 might be under 1GB. Knowing the file size before you render saves you from full drives, failed uploads, and wasted render time.
Plan Storage
Know if your drive has enough space before a 3-hour render completes.
Check Upload Limits
Verify your file will fit within platform upload limits before exporting.
Compare Codecs
See the size difference between H.264, H.265, and ProRes side by side.
Plan Transfer Time
Estimate how long uploads and transfers will take based on file size.
Frequently Asked Questions
The estimate is accurate to within 5โ15% for most video content. The formula uses bitrate ร duration, which is exact for CBR (Constant Bit Rate) encoding. For VBR encoding, actual file size varies based on content complexity โ action scenes use more data than static shots. Container overhead adds a small amount (typically under 1%).
ProRes is a lightly compressed intermediate codec designed for editing, not delivery. It preserves significantly more data per frame to maintain quality through multiple rounds of color grading and effects. H.264 is a heavily compressed delivery codec optimized for small file sizes. ProRes at 1080p typically runs 40โ175 Mbps vs 8โ16 Mbps for H.264 at the same resolution.
Switch to a more efficient codec. H.265 (HEVC) delivers the same visual quality as H.264 at roughly half the file size. AV1 is even more efficient โ about 30% smaller than H.265. If you can’t change codec, use 2-pass VBR encoding instead of CBR, which allocates more bits to complex scenes and fewer to simple ones.
Container overhead is the extra file size from the wrapper format (MP4, MKV, MOV) itself โ metadata, chapters, subtitle tracks, and index tables. It is typically under 1% for standard video files but can be larger if you embed many subtitle tracks, chapter markers, or attached files. This estimator includes a small overhead factor for accuracy.