Apple’s iPhone 18 Pro tech specs list 4K Dolby Vision recording at 24, 25, 30, 60, 100 and 120 fps, and ProRes video up to 4K at 120 fps with external recording. Those two lines decide more about which storage tier you need than anything else on the page, because one of them multiplies your footage by four and the other never touches the phone’s own storage.
Apple does not publish a data rate for any of these modes, so nobody can honestly tell you how many minutes fit in 256GB. What Apple does publish is resolutions, frame rates and, in one case, where the file is written. That is enough for the ratios below. Our iPhone 18 Pro camera explainer covers what the variable aperture changes; this is the storage half of the same decision.
Key facts: what Apple publishes about iPhone 18 Pro video
| Format | Apple’s published capability | Apple’s note on recording |
|---|---|---|
| 4K Dolby Vision | 24, 25, 30, 60, 100 or 120 fps | None, so it is written to the phone |
| Cinematic mode | Up to 4K Dolby Vision at 60 fps | None |
| ProRes | Up to 4K at 120 fps with external recording | External recording, in Apple’s own wording |
| Spatial video | 1080p at 30 fps | None |
| Time-lapse | 4K Dolby Vision HDR | None |
From Apple’s tech specs and its September 9 press release. Apple lists Apple Log 2, ProRes RAW and Genlock on the same phones and publishes a data rate for none of them. The A20 Pro and its media engine make the higher frame rates possible; they do not make the files smaller.
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The frame-rate multiplier
A minute of video is a stack of frames. At 120 fps the stack is four times as tall as at 30 fps, so at a constant cost per frame in the same codec and resolution it occupies about four times the space. That assumption is ours, and real encoders vary with how much movement is in the scene, but the scale of the effect is not in dispute.
| Setting | Frames in one minute | Storage per minute against 4K30 |
|---|---|---|
| 4K at 24 fps | 1,440 | 0.8x |
| 4K at 30 fps | 1,800 | 1x |
| 4K at 60 fps | 3,600 | 2x |
| 4K at 100 fps | 6,000 | 3.3x |
| 4K at 120 fps | 7,200 | 4x |
Our arithmetic on Apple’s published frame rates. A 1080p frame carries a quarter of the pixels of a 4K frame, which is why spatial video at 1080p30 is the lightest thing the camera records and why dropping from 4K to 1080p saves more than dropping from 120 fps to 60 fps.
What that does to the tier you buy
Set the camera to 4K120 and leave it there, and a 1TB iPhone 18 Pro holds what a 256GB phone would hold at 4K30. On Apple’s ladder, buying that difference back costs $600, the gap between the $1,199 256GB model and the $1,799 1TB model. That is our arithmetic on Apple’s Store prices, and it is the clearest way to price a settings change.
Turned around: an hour at 4K30, half an hour at 4K60 and a quarter of an hour at 4K120 all cost the same space. Most people do not shoot at the top setting all day, which is why the honest recommendation is to check what your current phone’s camera is set to before you pick a tier rather than after.
ProRes 4K120 is the exception that protects your storage
Apple qualifies the top ProRes mode with three words: with external recording. The heaviest format the phone can produce is therefore the one format that does not consume a byte of the tier you paid for, as long as you own a drive and a cable to put it on.
The port is USB-C with USB 3 at up to 10 Gb/s on both iPhone 18 Pro and iPhone 18 Pro Max. At eight bits to the byte that is 1.25 gigabytes a second, by our conversion, and that is the ceiling for the connection rather than a sustained write rate. Apple publishes neither a list of supported drives nor a minimum speed, so treat the drive as a purchase to research, not an afterthought.
What Apple has not said
Apple has published no bit rate or file size for 4K Dolby Vision, ProRes, ProRes RAW, Apple Log 2 or spatial video, so every figure above is a ratio rather than a capacity. It has not said which lower ProRes settings write internally, beyond the single line about 4K at 120 fps, and it has not published a minimum drive specification. It also does not say how much of each tier iOS 27 and the preinstalled apps occupy.
Pre-orders open at 5 a.m. PT on Saturday, September 12, with availability on Friday, September 18 in more than 65 countries. If you are choosing between two capacities, our iPhone 18 Pro against iPhone 18 Pro Max comparison sets out the other half of the order form, and the full announcement roundup has the rest.
