The iPhone 18 Pro is exactly the same size as the iPhone 17 Pro, and the 18 Pro Max is the same size as the 17 Pro Max. Same height, same width, same thickness. Only the weight went up a little.
So why won't your old case fit? Because the part that decides fit is not on Apple's spec sheet at all. It is the camera plateau on the back. Below you will find the iPhone 18 size in one simple table, what changed, and what that means for your case.
This matters most if your case does more than look good. With an iPhone 18 Pro and 18 Pro Max privacy case that covers the cameras, every cutout has to line up exactly.
The iPhone 18 size at a glance
All numbers come from Apple's own technical specifications. There is no regular iPhone 18 yet, so this article is about the iPhone 18 Pro and the iPhone 18 Pro Max.
| Model | Height | Width | Depth | Weight | Display |
|---|---|---|---|---|---|
| iPhone 18 Pro | 150.0 mm | 71.9 mm | 8.75 mm | 211 g (7.44 ounces) | 6.3 inch |
| iPhone 17 Pro | 150.0 mm | 71.9 mm | 8.75 mm | 206 g (7.27 ounces) | 6.3 inch |
| iPhone 18 Pro Max | 163.4 mm | 78.0 mm | 8.75 mm | 249 g (8.78 ounces) | 6.9 inch |
| iPhone 17 Pro Max | 163.4 mm | 78.0 mm | 8.75 mm | 233 g (8.22 ounces) | 6.9 inch |
Two things stand out. The Pro Max is clearly bigger than the Pro, so their cases are never interchangeable. And this year's Pro models are the same size as last year's, just a few grams heavier.
iPhone 18 Pro or Pro Max, which size suits you
The 18 Pro is the one you can comfortably use with one hand. The Pro Max is wider and the heaviest iPhone of this shape so far. If you take long calls or type while walking, you will notice the extra weight before you notice the bigger screen.
When you order a case, you pick your exact model. A Pro case will not fit a Pro Max, and the other way around.
A few other details worth knowing
Both models have an OLED (organic light-emitting diode) screen and are water and dust resistant down to 6 meters for up to 30 minutes. On the back, the three cameras sit in a plateau that runs the full width of the phone, with the LiDAR (light detection and ranging) scanner and the flash on the right. The phones come in black, silver, glacier and burgundy, with storage starting at 256GB.
If you are comparing models, all privacy cases with built-in camera covers are sorted by device.
Why the same size does not mean your case fits
Apple says iPhone 17 Pro cases are not compatible with the iPhone 18 Pro. The reason is the camera plateau, not the body. Apple's thickness figure only covers the body itself, not the raised camera area.
John Gruber measured the plateau with a digital caliper, as reported by MacRumors, and found it about a tenth of a millimeter higher than on the 17 Pro. Apple does not publish this number, so see it as a careful outside measurement.
A tenth of a millimeter sounds like nothing. With a slim case and a wide camera opening, it often is, and many 17 Pro cases still slide on. With a case that wraps around the cameras or has a cover over the lenses, it is enough to stop that cover from closing flush. Coming from an iPhone 16 Pro or older? Then the body itself is different and an 18 Pro case will not fit at all.
What this means for a case with a camera cover
A case with a sliding front cover and a flip-up rear cover has to be far more precise than a plain shell. The rear cover has to close over the lenses without touching the glass and stay shut in your pocket. The front slider has to fully cover the selfie camera when closed and leave Face ID free when open.
A small misalignment on a basic case is only cosmetic. On a camera cover it means the cover rests on the lens instead of around it. That is why you should always buy by exact model name. Our guide on how iPhone privacy cases are built and what to check before buying goes into more detail, just like our earlier look at camera cover cases for the iPhone 17 Pro Max.
Where the Spy-Fy iPhone 18 Pro case stands
The Spy-Fy privacy case for the iPhone 18 Pro and 18 Pro Max is made for the new plateau. It is matte black, MagSafe compatible and shock absorbing, and the rear camera cover doubles as a kickstand. The rear cover works as intended on both models.
The sliding front cover is a different story. The current version does not fully close over the front camera, so that part is being improved. That is why the case is on pre-order and why we stopped shipping the current version. Everyone who pre-orders gets an email as soon as the shipping date of the new version is confirmed. A camera cover that does not fully close is not something we want to ship and explain away later.
Ordering for your team or as a business gift? Check the fit and availability per model first, because a Pro case and a Pro Max case can never replace each other.
The takeaway on iPhone 18 size and case fit
The iPhone 18 Pro and Pro Max are the same size as the 17 Pro models, only slightly heavier. What decides whether a case fits is the camera plateau, and that is exactly why Apple says 17 Pro cases do not fit the 18 Pro. You can compare all Spy-Fy privacy cases by device.
Want to be first in line? Open the Spy-Fy privacy case for the iPhone 18 Pro and 18 Pro Max, choose your exact model and place a pre-order. You will get an email with the shipping date once it is confirmed, and you can cancel any time before it ships.
