iPhone 18 Pro Max Thickness Matches iPhone 17 Pro Max at 8.75mm

Weibo leaker Ice Universe revised the expected iPhone 18 Pro Max thickness today, dropping the figure from 8.8mm to 8.75mm and matching it exactly to the iPhone 17 Pro Max. The change, reported by AppleInsider today, came with no explanation.

Separate claims about a battery in the 5,100–5,200 mAh range, from Digital Chat Station, and a weight exceeding 240 grams, from Instant Digital, were not revised and remain open questions, per Trusted Reviews.

The 6.9-inch display footprint is expected to stay unchanged, per Trusted Reviews. Whether the phone gains anything meaningful inside that unchanged shell is the harder question, and the current evidence doesn’t answer it.

How the “thicker Pro Max” narrative built up

The thickness leak was the middle chapter of a longer rumor thread. Last November, Weibo leaker Instant Digital claimed the iPhone 18 Pro Max would be slightly thicker than its predecessor and could weigh over 240 grams, potentially making it the heaviest iPhone since the iPhone 14 Pro Max, MacRumors reported three months ago.

Ice Universe added a specific number three months ago: 8.8mm, up from 8.75mm on the iPhone 17 Pro Max. MacRumors described Ice Universe as an “oft-accurate” leaker, and the figure spread quickly as the working expectation for the device. Digital Chat Station then supplied a rationale: a battery in the 5,100–5,200 mAh range, up from the 5,088 mAh cell in the eSIM version of the iPhone 17 Pro Max, Trusted Reviews reported three months ago. The MacRumors Show tied it together in early April: a slightly thicker chassis, a bigger battery, a heavier phone.

The confidence was already softening before today. Two months ago, MacRumors noted that any thickness increase might be too small to show up on physical dummy units, a quiet signal the 8.8mm figure was under pressure heading into June.

What changed in the iPhone 18 Pro Max thickness leak and what didn’t

The difference between 8.8mm and 8.75mm is 0.05mm. No hand or pocket comparison would register it. The revision matters for a different reason: the same source changed a specific number with no stated rationale, while the battery and weight claims that formed the rest of the picture remain untouched.

Ice Universe’s updated figure appeared today with no explanation for the change, AppleInsider reported. Supply-chain leaks don’t come with changelogs.

Whether the revision reflects a different production sample, a shift in measurement methodology, or updated specs from further down the supply chain is unknown.

The battery estimate from Digital Chat Station is still 5,100–5,200 mAh, compared to 5,088 mAh in the current model, per Trusted Reviews.

That’s a claimed increase of up to roughly 112 mAh inside a chassis now rumored to be identical in thickness to its predecessor.

Battery chemistry improvements can yield modest capacity gains without added volume, so the pairing isn’t impossible, but nothing in the current evidence confirms it.

The weight claim, over 240 grams from Instant Digital, is also unrevised, according to MacRumors and Trusted Reviews. Both figures were originally part of the same case for a thicker chassis. The thickness changed; they didn’t.

iPhone 18 Pro Max vs iPhone 17 Pro Max: what’s actually different on the outside

Based on current leaks, not much. The 6.9-inch display footprint stays the same, per Trusted Reviews, and the revised 8.75mm thickness matches the iPhone 17 Pro Max exactly. For context, the iPhone 16 Pro Max measured 8.25mm, according to AppleInsider, meaning the Pro Max line has already stepped up in thickness across recent generations.

The more substantive changes are expected to be internal. The iPhone 18 Pro lineup is reported to include a smaller Dynamic Island, Apple’s in-house C2 modem, a simplified Camera Control system, and a main camera with variable aperture, per the MacRumors Show. Each of those changes consumes engineering resources without altering the phone’s outer dimensions.

In the same post that revised the thickness figure, Ice Universe claimed Apple directed its “attention and energy” toward the iPhone Ultra this cycle, AppleInsider reported today. It’s a plausible explanation for a static Pro Max chassis, but it comes from the same uncorroborated post as the revised thickness number, and no independent source has confirmed it

What the battery and weight claims mean for buyers

The gap between the two thickness figures was never going to affect anyone’s buying decision. The gap between a meaningful battery upgrade and an unchanged one is a different matter.

A phone that gains 100-plus mAh of capacity inside an identical shell, if the Digital Chat Station estimate holds, represents a real improvement for users who already find the Pro Max adequate in size. If that claim fades along with the original thickness argument that supported it, the picture changes.

A device that matches its predecessor in thickness, display size, and weight, with no confirmed capacity increase, is a maintenance release from a hardware standpoint. The camera, modem, and Dynamic Island changes would still matter to buyers upgrading from older models, but anyone on an iPhone 17 Pro Max would have limited hardware reasons to move.

The weight rumor complicates things further. A device that may exceed 240 grams, potentially the heaviest iPhone since the iPhone 14 Pro Max, per Trusted Reviews, combined with a battery increase of around 100 mAh, raises a fair question: where is the extra weight coming from? The current rumors don’t answer that, and no source in the available data offers an explanation.

Here the open questions sit now
The thickness number that dominated iPhone 18 Pro Max coverage for the past three months has been walked back by the person who set it, with no explanation offered. The new 8.75mm figure deserves the same skepticism as the 8.8mm claim it replaced.

The battery estimate of 5,100–5,200 mAh and the weight claim exceeding 240 grams are the more consequential unknowns, per Trusted Reviews. They have remained static through multiple rounds of revision from other sources, which is either a sign of reliability or simply the absence of updated information.

The signals worth watching: regulatory filings confirming actual battery capacity, dummy unit measurements from case manufacturers as the launch window approaches, and independent corroboration on the battery and weight figures from sources other than Ice Universe. The iPhone 18 Pro Max and iPhone 18 Pro are expected to launch later this year as part of Apple’s annual refresh, per Trusted Reviews. Until more concrete data arrives, the honest read is a phone that hasn’t changed where you can see it, with the changes below the surface still to be confirmed.