Phone and tablet screen sizes in cm: width, height and what fits
A 6.7-inch phone has a 17 cm screen diagonal, but the display is only about 15.5 cm wide and 7.1 cm tall at the common 19.5:9 shape. This guide converts phone and tablet sizes to centimeters, shows how the shape changes the numbers, and explains why the screen size alone never tells you whether a case, a holder or a pocket will fit.
What a phone or tablet size means
Phone and tablet sizes are the diagonal of the lit display in inches, the same convention as laptops and TVs. The body, bezel and frame are not included. If you want the method in detail, how to measure a TV screen explains it with the same diagonal rule.
The conversion is exact because one inch is 2.54 cm by definition (see the inches to cm chart and the NIST and BIPM sources on it). Width and height then follow from the aspect ratio: width = diagonal × a ÷ √(a² + b²), height = diagonal × b ÷ √(a² + b²). Every figure below is computed in code from the diagonal and rounded to one decimal.
Phone screens in cm
Modern phones are tall and narrow. The table uses 19.5:9, a very common ratio; your phone may differ slightly, so check its specification if you need millimeter accuracy.
| Screen size | Diagonal (cm) | Width (cm) | Height (cm) |
|---|---|---|---|
| 5.5″ | 14 | 12.7 | 5.9 |
| 6.1″ | 15.5 | 14.1 | 6.5 |
| 6.5″ | 16.5 | 15 | 6.9 |
| 6.7″ | 17 | 15.5 | 7.1 |
| 6.9″ | 17.5 | 15.9 | 7.3 |
Why a bigger phone is not that much wider
Because phones are tall, most of the extra diagonal goes into height. Moving from 6.1 to 6.9 inches adds 2 cm to the diagonal, but only 1.8 cm to the width and 0.9 cm to the height. For one-handed use the width is what counts, which is why a 6.9-inch phone feels less unwieldy than the number suggests.
Tablet screens in cm
Tablets are closer to square. The table lists common sizes with the typical ratio for each class: 3:2, 16:10 and 4:3.
| Screen size | Ratio | Diagonal (cm) | Width × height (cm) |
|---|---|---|---|
| 8.3″ | 3:2 | 21.1 | 17.5 × 11.7 |
| 10.2″ | 3:2 | 25.9 | 21.6 × 14.4 |
| 10.9″ | 3:2 | 27.7 | 23 × 15.4 |
| 11″ | 16:10 | 27.9 | 23.7 × 14.8 |
| 12.9″ | 4:3 | 32.8 | 26.2 × 19.7 |
Phone, tablet, laptop: how they compare
A 12.9-inch 4:3 tablet is 26.2 × 19.7 cm, which is close to the panel of a 13.3-inch laptop at 16:10 (28.6 × 17.9 cm). The laptop panel is wider; the tablet is taller. See laptop screen sizes in cm for the full laptop tables, and monitor sizes in cm when you want to know how a phone-sized view scales up to a desk screen.
What the screen size does not tell you
- The outside size of the device. The bezel and frame add a few millimeters on each side, and the amount differs by model. Use the manufacturer's height, width and thickness.
- Case and holder fit. A case is made for one exact model, not for a screen size. A "6.7 inch" case does not guarantee a fit across brands.
- Pocket or bag fit. Compare the device's outer dimensions in cm with the inside of the pocket, not the screen diagonal.
- How sharp the display is. That depends on resolution as well as on size.
Convert any screen size yourself
- Multiply inches by 2.54 for the diagonal in cm: 6.7 × 2.54 = 17.0 cm.
- Use the inches to cm converter for sizes that are not in the tables, or the cm to inches converter if you measured the screen diagonal with a ruler.
- For width and height, multiply the diagonal by the ratio factor shown earlier, or use the screen sizes in cm guide for the quick chart.
Frequently asked questions
How big is a 6.1 inch phone screen in cm?
The diagonal is 15.5 cm. At 19.5:9 the display is about 14.1 cm wide and 6.5 cm tall.
How many cm is a 6.7 inch phone?
17.02 cm along the screen diagonal. The phone body is larger than the screen, so check its dimensions in the specification.
How wide is a 6.9 inch phone screen?
About 15.9 cm wide and 7.3 cm tall at 19.5:9.
How big is an 11 inch tablet in cm?
An 11-inch 16:10 tablet has a 27.9 cm diagonal and a screen of 23.7 × 14.8 cm.
Does the phone screen size include the bezel?
No. It is the diagonal of the visible display only. The whole device is bigger.
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