Filesize,beforetherender.
Duration plus bitrate equals file size. Estimate storage and rough upload time before you commit to an export preset.
Video File Size Calculator
Variable-bitrate exports land a little under this figure; constant-bitrate exports land almost exactly on it. Add roughly 10% headroom when planning storage.
The whole formula
Size equals total bitrate multiplied by duration. A 10-minute 1080p export at 8 Mbps plus 384 kbps audio lands near 630 MB — useful to know before you start a transfer over hotel Wi-Fi.
Plan the drive, not the file
Multiply by the number of cutdowns, aspect ratios and language versions a campaign needs. A single 4K master is manageable; twelve deliverables from it is a storage decision.
Watch platform ceilings
Upload limits are usually expressed in gigabytes and minutes rather than bitrate. If an export is going to sit just over a limit, drop the bitrate a notch rather than re-cutting the video.
Add headroom
Variable-bitrate exports come in slightly under the estimate and constant-bitrate exports land almost exactly on it. Budget about 10% extra and you'll never be caught short.
How big is a 10-minute 1080p video?
Roughly 600–700 MB at an 8 Mbps delivery bitrate with 384 kbps audio. At a 20 Mbps mezzanine bitrate the same ten minutes is closer to 1.5 GB.
How big is a one-hour 4K video?
At 45 Mbps, about 20 GB. Editing-grade intermediate codecs such as ProRes are several times larger again, which is why they stay on the edit drive rather than travelling.
Why is my export bigger than the estimate?
Usually a higher maximum bitrate in a two-pass VBR preset, an uncompressed audio track, or an intermediate codec selected instead of a delivery codec.
Does resolution change file size on its own?
Indirectly. Size follows bitrate — but higher resolutions need higher bitrates to look clean, so in practice 4K files are far larger than 1080p ones.
Letushandletheexport.
Every deliverable leaves our room already sized, encoded and captioned for the platform it's going to.