The short version

iPhone 18 Pro Max: 6.43 x 3.07 x 0.34 inches (163.4 x 78.0 x 8.75 mm), 8.78 ounces (249 g), 6.9-inch display.
iPhone 18 Pro: 5.91 x 2.83 x 0.34 inches (150.0 x 71.9 x 8.75 mm), 7.44 ounces (211 g), 6.3-inch display.
Apple lists the same 0.34 inch (8.75 mm) depth as the iPhone 17 Pro and 17 Pro Max. The camera bar adds a little more.
The Pro Max is 16 grams heavier than the iPhone 17 Pro Max. The Pro is 5 grams heavier than the iPhone 17 Pro.
It went into a regular trouser pocket and came back out without a fight.

iPhone 18 Pro Max and iPhone 18 Pro dimensions and weight

These are the figures on Apple's iPhone 18 Pro specifications page, next to the two iPhone 17 Pro models from Apple's own tech specs.

Measurement	iPhone 18 Pro Max	iPhone 18 Pro	iPhone 17 Pro Max	iPhone 17 Pro
Height	6.43 in (163.4 mm)	5.91 in (150.0 mm)	6.43 in (163.4 mm)	5.91 in (150.0 mm)
Width	3.07 in (78.0 mm)	2.83 in (71.9 mm)	3.07 in (78.0 mm)	2.83 in (71.9 mm)
Depth	0.34 in (8.75 mm)	0.34 in (8.75 mm)	0.34 in (8.75 mm)	0.34 in (8.75 mm)
Weight	8.78 oz (249 g)	7.44 oz (211 g)	8.22 oz (233 g)	7.27 oz (206 g)
Display	6.9 in	6.3 in	6.9 in	6.3 in

Three things stand out. The Pro Max and the Pro are the same thickness, so the choice between them comes down to height, width and weight: the Max is 0.52 inch (13.4 mm) taller, 0.24 inch (6.1 mm) wider and 1.34 ounces (38 grams) heavier. Neither phone changed its height, width or listed depth from last year. And both got heavier, the Pro Max by 16 grams (0.56 ounce) and the Pro by 5 grams (0.17 ounce).

Apple adds that size and weight vary by configuration and manufacturing process. The 6.9 inches is the diagonal, and Apple's fine print puts it at 6.86 inches measured as a standard rectangle, with a little less viewable area because of the rounded corners.

Matching outer dimensions do not tell you whether last year's cases fit, and I have not tried one. If you are not sure what you are upgrading from, here is how to check which iPhone you have before you compare numbers.

How big is the iPhone 18 Pro Max in the hand?

It's the big one. The screen is 6.9 inches, and it weighs just under nine ounces, which is a little over half a pound.

The back of a silver iPhone 18 Pro Max held upright in one hand over colored paving — The bottom edge sits on the heel of my palm and the camera bar clears my index finger. Photographed with my iPhone 17 Pro.

With the bottom edge resting on the heel of my palm, my fingers wrap around the lower two thirds of the phone and the whole camera bar sits clear above them. Face up in my open hand, it leaves the base of my thumb showing on one side and my fingertips on the other.

The front of the iPhone 18 Pro Max with the screen off, lying in an open palm above a desk — Screen off at my desk, on the day I unboxed it. The open box behind it holds the USB-C cable.

When I turned it over in two hands, one hand took the camera end and the other took the bottom, with the Apple logo showing in the gap between them.

The back of the iPhone 18 Pro Max held between two hands over asphalt — One hand at the camera bar, one at the bottom edge, and the middle of the back still uncovered.

These photos show the phone held in one hand and in two hands. Cases are untested.

iPhone 18 Pro Max next to the iPhone 17 Pro

My other phone is an iPhone 17 Pro, the 6.3-inch model. Apple lists the iPhone 18 Pro at the same height, width and depth as the 17 Pro, so this photo doubles as a rough guide to how the 18 Pro Max sits next to the smaller 18 Pro.

The top halves of an iPhone 17 Pro in a clear case and an iPhone 18 Pro Max lying side by side on a dark desk, both screens on — Shot straight down with both phones flat. Compare the screens, not the outer edges, because the 17 Pro is wearing a case.

Two cautions. My 17 Pro is in a clear case, which makes it look wider than it is, so compare the screens and not the outer edges. And the photo shows only the top of each phone. I shot it straight down with both phones flat on the desk, and in the original the two screens measure 1,414 and 1,548 pixels across. That ratio, 1.095, is what 6.9 inches divided by 6.3 inches comes to, so the scale is true.

One thing did get smaller. With nothing running, the Dynamic Island on the 18 Pro Max is about 24 percent narrower than my 17 Pro's in that photo. A report we covered in March had put the shrink at 35 percent.

How thick is the iPhone 18 Pro Max?

Apple lists 0.34 inch (8.75 mm) for both the Pro Max and the Pro. Side on, it's about a third of an inch thick, and the camera bar adds a little more.

Edge-on. The rail is flat, and the camera lenses stand out past the back on the left.

Before launch, a report we covered in July said the iPhone 18 Pro would be roughly 2 mm thicker than the iPhone 17 Pro. Apple's spec pages do not show that. The iPhone 17 Pro and 17 Pro Max are listed at 0.34 inch (8.75 mm), and so are the iPhone 18 Pro and 18 Pro Max. Apple's spec page does not explain whether its depth figure includes the camera bar. The dimensions here are Apple's published figures, and the photos show the raised bar separately.

Three buttons on this side, a flat rail and rounded corners.

That is the same edge at my desk on the day I unboxed it.

The bottom edge of the iPhone 18 Pro Max held in a hand, showing the USB-C port and a row of holes on each side — The USB-C port gives the edge some scale.

From the bottom, the USB-C port sits in the middle with a row of holes on either side. The whole edge is thinner than the fingertips holding it.

The camera bar stands proud of the back

The camera bar runs all the way across the back and sits above it. A three-quarter view shows both halves of the story, a slim rail and a raised bar.

A three-quarter view of the iPhone 18 Pro Max in one hand, showing the side rail, two buttons and the raised camera bar — The rail is slim. The bar and its three lens rings are not trying to be.

Held flat and photographed from the side, the step is easy to read. The bar sits above the back, and the three lens rings sit above the bar.

The iPhone 18 Pro Max held flat and seen from the side, with the camera bar and lenses rising above the back — Two steps up from the back: first the bar, then the lens rings.

Apple's spec page gives no separate height for the camera bar. The bar carries the three rear camera lenses, including the main camera with the variable aperture Apple added this year. It is also how the phone greets you. Lift the lid of the box and the phone is face down in the tray, so the first thing you see is that bar.

The iPhone 18 Pro Max lying face down in its white box tray, seen from a low angle with the camera bar nearest the lens — Face down in the tray, straight out of the box. From this low the bar reads as a shelf across one end.

Up close, the bar has its own raised edge all the way around, and it makes the camera end the thickest part of the phone. That matters for the next test.

A close view of the iPhone 18 Pro Max camera bar with three lenses, the flash and a sensor, held sideways against a cream shirt — The raised lip runs around the whole bar.

Does the iPhone 18 Pro Max fit in a pocket?

A viewer asked under my first video of this phone, "Is it small?" It is not. The fairer question is whether the big one still goes in a pocket, so I took it for a walk and tried it at the start of the afternoon and again nearly three hours later.

A hand pushing the iPhone 18 Pro Max, camera end first, into the pocket of navy trousers — Camera end first, which is the thickest end of the phone.

It slides into a regular trouser pocket, camera end first, and it comes back out without a fight.

Three video frames of the iPhone 18 Pro Max held at the hip, tipping into a front trouser pocket, and almost fully inside it — Three frames from one clip, about a second apart: at my hip, tipping in, and nearly gone.

Coming out is the same move in reverse. The bottom of the phone appears first, and the camera bar is the last part to clear the pocket.

Three video frames of the iPhone 18 Pro Max being drawn out of a front trouser pocket, ending with the whole phone in the hand — From an earlier pocket clip, about three hours before the frames above. The camera bar leaves the pocket last.

What these frames do not show is the pocket with my hand out of it, so I am not going to claim the phone disappears completely. They show a trouser pocket while standing, and they do not establish fit when seated, in other kinds of pockets, or with a case on. I can only vouch for the trousers I was wearing.

How heavy is the iPhone 18 Pro Max?

Apple lists 8.78 ounces (249 grams). That is 16 grams more than the iPhone 17 Pro Max, 38 grams more than the iPhone 18 Pro, and 43 grams (about an ounce and a half) more than my iPhone 17 Pro. The weight quoted here is Apple's published figure.

Apple does not say where the extra grams went, and its spec page does not list a battery capacity. An August report we covered pointed to a larger battery in the Pro Max, based on leaked images.

Is the iPhone 18 Pro Max too big?

It's not small, but it's not a brick either. If it still sounds like too much phone, the iPhone 18 Pro is about half an inch shorter, a quarter of an inch narrower and 38 grams lighter at the same thickness.

What I can't tell you yet is how it wears over time. I unboxed it on October 11 and took these photos that day and the next afternoon. Battery life across days, heat, durability and life in a case are all untested.

If you are moving up from an older iPhone, our guide to transferring data to a new iPhone walks through the phone-to-phone transfer I used to set this one up.

More from my iPhone 18 Pro Max testing

This product was provided to Technobezz for review. We independently select what we review. The manufacturer had no input on this article and did not see it before publication. All opinions are our own.