How to use the Phone PPI Calculator
Enter the advertised diagonal screen size and the horizontal and vertical resolution. The calculator returns PPI, pixel pitch, total pixels, and a practical sharpness label for handheld screens.
Phone PPI is most useful when comparing screens with different sizes. A larger phone can have more pixels but lower density if the pixels are spread across a bigger display.
If you are comparing desktop displays, use the Monitor PPI Calculator. For physical screen width, height, and area comparisons, use the Screen Size Comparison Calculator.
Phone PPI formula
diagonal pixels = sqrt(horizontal pixels^2 + vertical pixels^2)PPI = diagonal pixels / screen diagonal inchespixel pitch (mm) = 25.4 / PPIThe formula uses the pixel diagonal and the physical screen diagonal. This is why both resolution and screen size are needed to judge phone screen density.
Assumptions and methodology
This calculator treats the advertised screen size as the visible diagonal and uses the native display resolution. It estimates physical pixel density, not panel quality, subpixel layout, brightness, sharpening, or operating system scaling.
- PPI is calculated from diagonal pixels and diagonal inches.
- Pixel pitch is the physical size of one pixel in millimeters.
- The 20/20 visibility distance uses one arcminute as a simplified visual acuity threshold.
- Real sharpness also depends on viewing distance, font rendering, OLED or LCD subpixel layout, and eyesight.
Example calculations
6.7-inch 2400 x 1080 phone
A 6.7-inch 2,400 x 1,080phone screen has about 393 PPI, a pixel pitch of 0.065 mm, and 2.59 million pixels. That is a sharp density for a typical handheld viewing distance.
Phone and tablet PPI chart
These examples compare common phone, foldable, and tablet screen sizes. Use the calculator above for exact custom specifications.
| Device type | Size | Resolution | PPI | Pixel pitch | Density |
|---|---|---|---|---|---|
| Compact phone | 5.4 in | 2340 x 1080 | 477 | 0.053 mm | Sharp |
| 6.1 in phone | 6.1 in | 2532 x 1170 | 457 | 0.056 mm | Sharp |
| 6.7 in phone | 6.7 in | 2400 x 1080 | 393 | 0.065 mm | Good |
| 6.8 in QHD phone | 6.8 in | 3088 x 1440 | 501 | 0.051 mm | Very sharp |
| 7.6 in foldable | 7.6 in | 2176 x 1812 | 373 | 0.068 mm | Good |
| 8.3 in tablet | 8.3 in | 2266 x 1488 | 327 | 0.078 mm | Good |
| 11 in tablet | 11 in | 2360 x 1640 | 261 | 0.097 mm | Basic |
| 12.9 in tablet | 12.9 in | 2732 x 2048 | 265 | 0.096 mm | Basic |
Related calculators
TV Dimensions Calculator
Convert diagonal TV size into approximate screen width and height.
TV Resolution Calculator
Compare 1080p, 4K, and 8K detail based on TV size, viewing distance, and visual acuity.
Monitor PPI Calculator
Calculate monitor pixel density, pixel pitch, and perceived sharpness from screen size and resolution.
Screen Size Comparison Calculator
Compare screen area, width, height, and size differences between displays.
FAQ
How do I calculate phone PPI?
Calculate the diagonal pixel count using the horizontal and vertical resolution, then divide it by the screen diagonal in inches. That gives pixels per inch, or PPI.
What is a good PPI for a phone?
Around 400 PPI is already sharp for many phones at normal handheld distance. Higher values can look very crisp, but the difference becomes harder to notice as PPI gets very high.
Is 400 PPI enough for a phone?
Yes for most users. The default example in this phone PPI calculator is about 393 PPI, which is a sharp handheld display density for everyday reading, browsing, and video.
Is QHD sharper than FHD on a phone?
Usually yes. For example, a 6.8-inch 3088 x 1440 screen is about 501 PPI, which is much denser than a typical 6.7-inch 2400 x 1080 phone. Battery life, scaling, and content quality still matter.
Why do tablets have lower PPI than phones?
Tablets are larger and are usually held farther away, so they can look sharp at lower PPI. An 11-inch 2360 x 1640 tablet is about 261 PPI, which can still feel clear at normal tablet viewing distance.
Is PPI the same as resolution?
No. Resolution is the pixel count, such as 2400 x 1080. PPI also includes physical screen size, so the same resolution looks denser on a smaller screen and less dense on a larger screen.