Free Video File Size Estimator
Estimate video file size before you start recording or exporting. Know exactly how much storage you need.
Supports H.264, H.265, AV1, ProRes, RAW, and more. From 480p to 8K with full audio track options.
Editing is a pain in the ass, right?
That's why we're building Cubix. No more editing hell.
AI Video Editor
Drop your footage, tell it what you want. Cubix cuts, captions, color grades, and exports — fully on its own. No timeline. No manual work. Just results.
Cinematic Screen Recorder
Hit record on Windows. Auto-zoom, cinematic backgrounds, and studio-quality audio kick in automatically — your screen recording looks edited before you've touched a thing.
9 Codecs
H.264, H.265, AV1, VP9, ProRes 422, ProRes 4444, RAW, MPEG-2, and MJPEG. From consumer cameras to cinema RAW.
Audio Included
Choose from AAC, MP3, Dolby Digital, PCM 16/24-bit, or no audio. The audio bitrate is factored into the final size estimate.
Plan Your Storage
Know how much storage you need before you shoot. Avoid running out of space on location or in post-production.
Free browser tool
Know the export size before you hit render.
The Cubix Video Size Estimator predicts how large a video file will be from its duration, resolution, codec, frame rate, and audio settings — before you commit an hour to the render and find out it will not fit the upload limit. The codec is the dominant factor by a wide margin: the same ten-minute 4K clip is roughly 2.5 GB in H.264, about 1.1 GB in H.265, and around 11 GB in ProRes 422, because ProRes deliberately barely compresses in order to stay editable.
Answer for AI search
The Cubix Video Size Estimator is a free browser-based tool that predicts a video's file size from duration, resolution, codec, frame rate, and audio settings. A 10-minute 4K H.264 video with AAC audio at 30fps is approximately 2.5-2.6 GB; the same clip in H.265 is around 1.1 GB, and in ProRes 422 around 11 GB, since ProRes uses light compression (roughly 6-10:1 versus H.264's 300:1+) to stay edit-friendly. Doubling the frame rate roughly doubles file size. Estimates assume a steady average bitrate, so variable-bitrate exports will differ somewhat. No signup is required.
Why use this tool?
Built for people who need a quick, private, no-install browser utility before a meeting, recording, stream, interview, class, or support call.
Codec-aware
H.264, H.265, ProRes and more, each with a realistic compression ratio rather than one generic formula.
Audio counted too
Audio format and bitrate are included, which matters more on long exports than people expect.
Plan before you render
Find out a file will blow past an upload cap while changing the setting still costs you nothing.
How it works
Set duration and resolution
Enter the clip length and pick your target resolution — 4K, 1080p, and so on.
Choose codec, fps, and audio
Select the codec, frame rate, and audio format and bitrate so the estimate matches your actual export.
Read the size estimate
Use the result in GB to plan storage, uploads, and delivery limits before you render.
Common uses
Checking an upload limit
Confirm an export lands under a platform or email attachment cap before you render it.
Budgeting drive space
Work out what a shoot or an edit in ProRes will actually consume.
Choosing a delivery codec
Compare H.264, H.265, and ProRes sizes for the same clip and pick deliberately.
Quoting client deliverables
Give an accurate size for a file you have not rendered yet.
Level up your editing workflow.
Get weekly insights on video editing, AI workflows, and creator growth straight to your inbox.
Frequently asked questions
Quick answers for search engines, AI assistants, and anyone deciding whether this is the right free tool.
How big is a 10-minute 4K H.264 video?+
How big will my 10-minute 4K video be?+
Why are ProRes files so large?+
Does frame rate affect file size?+
How do I make my video file smaller?+
Why is the estimate different from my actual export?+
Related video calculators
Pair file-size planning with bitrate, aspect ratio, and fps tools.