iPhone Duo dimensions: 4.64 by 3.31 inches closed, 6.48 inches wide open and 8.96 ounces

The iPhone Duo is short and wide when closed and thinner than any other iPhone when open. Here are its official dimensions and weight, and how they compare with the iPhone 18 Pro Max, the iPhone Air and the iPad mini.

IPhone Duo dimensions closed

Closed, the iPhone Duo is 4.64 inches tall, 3.31 inches wide and 0.44 inch thick, or 117.8 by 84.1 by 11.3 mm, according to Apple’s spec sheet. That makes it a short, wide phone, and Apple compares it to the size of a passport.

The closed phone uses its 5.4-inch outer screen, which Apple says has 90 percent of the screen area of the iPhone 18 Pro. Apple moved the essential controls to the side so they’re easy to reach one-handed, and says the layout leaves more vertical space for apps.

IPhone Duo dimensions open

Opened like a book, the iPhone Duo is 6.48 inches wide and 0.21 inch thin, or 164.6 by 5.2 mm, at the same 4.64-inch (117.8 mm) height. At 5.2 mm, it’s the thinnest iPhone Apple has made, thinner than the 5.64 mm iPhone Air.

The open phone shows its 7.6-inch inner screen, which Apple says is 50 percent larger than the screen on the iPhone 18 Pro Max. Apple keeps the same aspect ratio on the inner and outer screens.

How much does the iPhone Duo weigh?

The iPhone Duo weighs 8.96 ounces, or 254 grams, whether it’s open or closed. That’s 5 grams more than the iPhone 18 Pro Max at 249 grams, 43 grams more than the iPhone 18 Pro at 211 grams and 89 grams more than the iPhone Air at 165 grams.

For a phone with two screens and two batteries, that puts it within a few grams of the biggest single-screen iPhone. Weight is the same in both positions, so the open phone is lighter than Apple’s smallest iPad, at 254 grams against 293 grams for the Wi-Fi iPad mini.

IPhone Duo vs iPhone 18 Pro Max and iPhone 18 Pro

The iPhone 18 Pro Max measures 163.4 by 78.0 by 8.75 mm (6.43 by 3.07 by 0.34 inches). Closed, the iPhone Duo is 45.6 mm shorter, 6.1 mm wider and 2.55 mm thicker. Open, it’s 164.6 mm wide, more than twice the width of the Pro Max, and 3.55 mm thinner.

The iPhone 18 Pro measures 150.0 by 71.9 by 8.75 mm. Closed, the Duo is 32.2 mm shorter and 12.2 mm wider, so it sits lower in a pocket but takes more room side to side. Our iPhone 18 page has the full iPhone 18 lineup.

IPhone Duo vs iPhone Air

The iPhone Air measures 156.2 by 74.7 by 5.64 mm and weighs 165 grams. The open iPhone Duo beats it on thinness by 0.44 mm, which is why Apple calls the Duo the thinnest iPhone ever. Closed, though, the Duo is twice as thick as the Air and 89 grams heavier, so the two phones answer very different needs.

IPhone Duo vs iPad mini

The iPad mini measures 195.4 by 134.8 by 6.3 mm and weighs 293 grams for the Wi-Fi model and 297 grams with cellular. The open iPhone Duo is 30.8 mm shorter on its long side, 17.0 mm shorter on its short side, 1.1 mm thinner and 39 grams lighter than the Wi-Fi iPad mini.

The screens are closer than the bodies: 7.6 inches on the Duo against 8.3 inches on the iPad mini. Our iPad mini 8 page covers the next iPad mini.

Screen sizes and resolution

The 7.6-inch inner screen has a resolution of 2670 by 1878 pixels at 430 pixels per inch, with a nano-texture finish that cuts glare and, Apple says, minimizes how visible the crease is. The 5.4-inch outer screen has 2034 by 1398 pixels at 460 pixels per inch. Apple measures both screens as rectangles, at 7.58 and 5.36 inches, and the corners are rounded.

Titanium frame and hinge

Apple builds the iPhone Duo from grade 5 titanium with a mirror-polished finish, in star white and night sky. The 3D-printed hinge cover is made from 100 percent recycled titanium and has a contrasting micro-blasted finish. Apple says the hinge has more than 100 components, supports the center of the screen to hold it flat when open and closes securely with a built-in magnet array.

The front has Ceramic Shield 2 and the back Ceramic Shield, the inner screen has a scratch-resistant coating, and the phone is rated IP68, to 6 meters for up to 30 minutes.

IPhone Duo cases and how they change the size

Apple sells two cases for the iPhone Duo on its US store. The iPhone Duo Case, in sand and navy blue, costs $79 and has a two-part design that wraps around both halves of the phone. The iPhone Duo Folio with Kickstand, in navy blue and taupe, costs $129 and adds a kickstand for viewing and FaceTime. Both work with MagSafe, Qi2 25W and Qi-certified chargers.

Either case adds thickness to the 11.3 mm closed body, so plan pocket space with the case on. Our iPhone Duo case page compares the two.

Price and availability

The iPhone Duo costs $1,999 for 256GB in the US, with 512GB, 1TB and 2TB models, and goes on sale on Oct. 23, 2026. New orders on Apple’s US store were quoted for Jan. 22, 2027, as our iPhone Duo ship date page explains, and our iPhone Fold release date and price page covers the full launch. Prices in Canada, the UK and India are on our iPhone Duo price in Canada page.

This page is updated as soon as Apple changes the iPhone Duo spec sheet or lists new cases for it.