Fit guide

Will an iPhone 17 Pro Max case fit an 18 Pro Max?

Apple gives the 18 Pro Max exactly the same dimensions as the 17 Pro Max. What that does and doesn’t tell you about cases, and why we cut each one per model.

Written by the YOONIG team · Editorially reviewed · Updated 10 Nov 2026 · 3 min read

The short answer

Not confirmed. Apple’s spec pages give the 18 Pro Max exactly the same height, width and depth as the 17 Pro Max (163.4 × 78 × 8.75 mm), the same 6.9-inch screen, USB-C, an Action button and Camera Control.

What a spec table can’t show is whether the camera opening, button cut-outs and microphone holes sit in exactly the same places. Apple doesn’t say the cases are shared: it sells separate cases and lists a single model under compatibility on each one (for example its iPhone 18 Pro silicone case). Every YOONIG case is cut for one model too, so pick the case for the phone you own.

Side by side

Official dimensions from the manufacturer. Dimensions alone don’t decide fit: camera position, button placement and cut-outs matter just as much.

Sources: iPhone 17 Pro Max specs, iPhone 18 Pro Max specs.

Official manufacturer figures, rounded as published.
Spec	iPhone 17 Pro Max	iPhone 18 Pro Max
Height	163.4 mm	163.4 mm
Width	78 mm	78 mm
Depth	8.75 mm	8.75 mm
Screen	6.9-inch	6.9-inch
Charging port	USB-C	USB-C
Side buttons	Action button, Camera Control	Action button, Camera Control
MagSafe	Yes	Yes

What the specs show

Nothing in Apple’s published specs differs between the two in the places a case cares about: size, port and side buttons. That still isn’t the same as confirmed matching cut-outs.

Apple lists exactly the same height, width and depth for both

What the spec sheets can and can’t tell you

Matching dimensions mean a case for one is the right overall size for the other. They don’t tell you where the lenses sit, how far the camera module sticks out, or exactly where each button is. Those decide whether a case covers a button, rests on the camera rim or leaves a gap.

The same goes for the smaller pair: the 18 Pro shares the 17 Pro’s dimensions (150 × 71.9 × 8.75 mm). See will an iPhone 17 Pro case fit an iPhone 18 Pro.

Coming from a 16 Pro Max?

That one is a clear no: the 16 Pro Max is 163 × 77.6 × 8.25 mm, a different size from both the 17 Pro Max and the 18 Pro Max. More in will a 16 Pro Max case fit a 17 Pro Max.

Spec	iPhone 16 Pro Max	iPhone 17 Pro Max	iPhone 18 Pro Max
Height	163 mm	163.4 mm	163.4 mm
Width	77.6 mm	78 mm	78 mm
Depth	8.25 mm	8.75 mm	8.75 mm
Screen	6.9-inch	6.9-inch	6.9-inch
Charging port	USB-C	USB-C	USB-C
Side buttons	Action button, Camera Control	Action button, Camera Control	Action button, Camera Control
MagSafe	Yes	Yes	Yes

Why “almost fits” isn’t good enough

A case that nearly fits can press a side button all the time, leave a gap at one corner where the phone can pop out when dropped, or sit on the camera rim so the lenses touch the table. A raised edge around the camera only protects if it surrounds the lenses exactly.

Every YOONIG case is cut for one model, so the print, the openings and the raised edges line up with that phone. If you are not sure which model you have, our guide to finding your exact model takes a minute.

Find the right case

Shop cases made for each phone: iPhone 17 Pro Max cases, iPhone 18 Pro Max cases.

Frequently asked questions

Are the iPhone 17 Pro Max and 18 Pro Max the same size?

Apple lists the same dimensions for both: 163.4 × 78 × 8.75 mm.

Will an 18 Pro Max case fit a 17 Pro Max?

Matching dimensions are a good sign but not proof. Apple lists separate cases for each model, and the camera, button and microphone openings need to line up. Choose a case listed for your exact model.

Will a 16 Pro Max case fit an 18 Pro Max?

No. The 16 Pro Max (163 × 77.6 × 8.25 mm) is a different size.

Is there an iPhone 18 Plus?

As of November 2026, Apple’s spec pages list the iPhone 18 Pro and 18 Pro Max; there is no iPhone 18 or 18 Plus listed.