Video File Size Calculator
Bitrate times duration. Resolution does not enter into it.
Work out Video File Size. Bitrate times duration. Resolution does not enter into it. Answers in the units the job actually uses.
File size
22.5 GB
50 Mbps for 60 minutes
File size is bitrate times duration, and nothing else. Resolution and frame rate matter only through the bitrate you choose to encode at — a 4K file at 20 Mbps is exactly the same size as a 1080p file at 20 Mbps, and looks considerably worse. Bits and bytes are the usual trap. Bitrate is quoted in megabits per second and storage in megabytes, a factor of eight apart, which is also why a 100 Mbps connection uploads at about 12 MB a second at best. Camera bitrates run far above delivery bitrates on purpose. Recording at 400 Mbps and delivering at 15 gives the grade and the encoder room to work; recording at delivery bitrate throws that away before you start.
How the Video File Size Calculator works
Work out the file size of a recording from its bitrate and length, plus how long it will take to upload. Resolution and frame rate change the size only through the bitrate you choose — a 4K file at 20 Mbps is exactly the same size as a 1080p file at 20 Mbps.
Also known as: how much storage for an hour of 4k · how big will my video be · what size card do I need for filming · how long to upload a video
Frequently asked questions
How much storage does an hour of 4K video need?
Entirely dependent on bitrate. An hour at 100 Mbps is 45 GB; the same hour at 15 Mbps streaming bitrate is 6.75 GB. Camera codecs run far higher than delivery codecs, which is why card requirements surprise people.
Why is my 100 Mbps connection uploading at 12 MB a second?
Because bitrate is quoted in megabits and file size in megabytes — a factor of eight. 100 Mbps is 12.5 MB per second at the theoretical maximum, and rather less in practice.
Does higher resolution always mean a bigger file?
Only if you raise the bitrate to match, which you generally should. Size is bitrate times duration and nothing else; encoding 4K at 1080p bitrates produces a normal-sized file that looks worse than the 1080p original.
Should I record at delivery bitrate to save space?
No. Recording high and delivering low gives the grade and the final encoder room to work. Once detail is discarded at capture it cannot be recovered, and re-encoding an already-compressed file compounds the artefacts.
How much card do I need for a shoot?
Take the camera's bitrate, multiply by the recording time you expect and add at least 30%. The hours-per-terabyte row makes the comparison quick across formats.
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