My laptop is HP 250 G2 with 15.6” diagonal LED-backlit HD2 anti-glare (1366 x 768). Please How do I know the dpi value?
1366 x 768 pixels is 1567 pixels diagonally (Pythagorean theorem, √(13662+7682)=1567; and you thought you would never use that).
If the screen measures 15.6" diagonally, 1567 pixels / 15.6" is approximately 100 pixels per inch.
You won't get an exact PPI number unless the manufacturer publishes it or you measure the screen. The advertised diagonal measurement is often a nominal number and may include a little of the display panel behind the bezel.
Assuming you are using Windows 7:
- Go to
Appearance and Personalization>
- In the left(blue) column, click
Set custom text size(DPI)
A window titled
Custom DPI Scaling will pop up.
It will show what percent of the "normal size"(default monitor DPI) it is scaled to and will allow you to adjust it.
You should see a ruler in the middle. Below that it will say 9 point Segoe UI at X pixels per inch.
The X is your current DPI.
as of DPI Calculator
- Display size: 13.6" × 7.65" = 103.96in² (34.54cm × 19.42cm = 670.72cm²)
- DPI = PPI = 100.45
- 0.2529mm dot pitch, 10091 PPI²
Try yourself: DPI Calculator
PPI = √(pixels_horizontal^2 + pixels_vertical^2) / inches_diagonal
PPI = √(13662 + 7682) / 15.6 = 100.45
Therefore, 100.45 dpi