4K video on iPhone uses roughly 6-7 GB per hour at 60fps (about 400 MB per minute), so a "low storage" warning can stop a recording fast. To make room quickly, delete your largest existing videos, empty Recently Deleted, and offload a couple of big apps — then, to record longer, drop the camera to 4K/30 or 1080p in Settings, which roughly halves the file size.
TL;DR
- 4K/60 ≈ 6-7 GB per hour (~400 MB/min); 4K/30 is about half that.
- Free space fast: delete your biggest old videos + empty Recently Deleted.
- Record more by switching Settings > Camera > Record Video to 4K/30 or 1080p.
- Offload a big app or two for a quick extra gigabyte.
- HEVC ("High Efficiency") format roughly halves video size vs "Most Compatible".
How much space does 4K video need?
At 4K/60fps, iPhone records about 400 MB per minute — roughly 6-7 GB per hour. 4K/30 is about 170 MB/min, and 1080p/30 around 65 MB/min. So if you are about to film an event, you may need several gigabytes free, far more than the clip you are replacing.
Free space fast before recording
- Delete your largest videos — Photos > Albums > Media Types > Videos; remove a few old long clips (each can be gigabytes). (See how to find and delete large videos.)
- Empty Recently Deleted — Photos > Albums > Recently Deleted > Delete All.
- Offload a big app — iPhone Storage > [app] > Offload App for a quick extra GB.
Record more by lowering the setting
Settings > Camera > Record Video — choose 4K at 30 fps (half the size of 4K/60) or 1080p at 30 fps for the smallest files. Also confirm Settings > Camera > Formats > High Efficiency (HEVC) is on — it roughly halves size versus "Most Compatible".
What iOS does natively, and where it stops
iOS lets you change the recording resolution and format, which is the real lever for fitting more video. What it will not do is find and clear your existing large videos for you — you scan the Videos album manually. That hunt is the slow part when you are in a hurry.
What this cannot do
Lowering the resolution shrinks new recordings but does nothing to existing files — clear those separately. And HEVC files are smaller but slightly less compatible with very old devices/apps; switch to "Most Compatible" only if you hit a playback issue.
FAQ
How much storage does 4K video use on iPhone?
About 6-7 GB per hour at 4K/60fps (~400 MB per minute). 4K/30 is roughly half, and 1080p/30 is far smaller.
How do I free up space fast to record a video?
Delete your largest existing videos, empty Recently Deleted, and offload a big app. Then lower the camera resolution to record longer.
How do I make iPhone videos take less space?
Set Settings > Camera > Record Video to 4K/30 or 1080p, and keep Formats > High Efficiency (HEVC) on — that roughly halves file size.
Does lowering resolution affect videos I already filmed?
No. It only applies to new recordings. To shrink existing clips, compress or remove them separately.
Next: how to find and delete large videos on iPhone without deleting photos and how to free up 10GB on iPhone in 10 minutes. To clear space in one pass, get Cleanor for iPhone.