Case 1
- Pixel density
- 109ppi
0.23303mm
Open with these valuesDot Pitch Calculator
0.23303mm
Result: 0.23303 mmAn inch is exactly 25.4 mm, so the distance between two pixel centres is 25.4 ÷ PPI. A 109 PPI desktop monitor has a dot pitch of 0.233 mm; a 326 PPI phone sits at 0.078 mm, which is why its pixels stay invisible at reading distance.
Worked examples
Case 2
- Pixel density
- 96ppi
0.26458mm
Open with these valuesCase 3
- Pixel density
- 326ppi
0.07791mm
Open with these valuesHow it's calculated
dot pitch = 25.4 mm ÷ PPI
- StepEnter the pixel density of the screen in pixels per inch.
- StepDivide 25.4 mm, the length of one inch, by that number.
- ResultRead the centre-to-centre distance of neighbouring pixels.
What this number means
Smaller is finer, so a low figure wins
The pitch measures from one pixel centre to the next, so less distance means a finer image at the same viewing distance. A 109 PPI monitor sits at 0.233 mm, a 326 PPI phone at 0.078 mm.
The inch is exact, so the result is too
An inch is defined as exactly 25.4 millimetres, not rounded from something else. The pitch is nothing more than that length shared out over the pixels of one inch.
Viewing distance decides what looks sharp
Roughly 0.23 mm and below reads as sharp at arm's length, which is about 109 PPI. A phone is held far closer and needs a much smaller pitch to look the same.
Commonly misread
A bigger dot pitch number means a sharper screen.
It is the other way round, because the number is a distance. The 0.078 mm of a phone is finer than the 0.265 mm of a 96 PPI reference screen.
Dot pitch is counted in pixels.
It is a length in millimetres between two pixel centres. The pixel density per inch is what you put in, not what comes out.
Dot pitch and pixel pitch are two different measurements.
On LCD and OLED panels they are the same thing. Only on old shadow-mask tubes did dot pitch describe the phosphor triads, which did not match the addressable pixels.
Reference table
| PPI | Typical screen | Dot pitch (mm) |
|---|---|---|
| 1 | One pixel per inch | 25.40000 |
| 96 | Classic desktop reference | 0.26458 |
| 109 | 27-inch 1440p monitor | 0.23303 |
| 163 | Handheld console | 0.15583 |
| 326 | Retina-class phone | 0.07791 |
Questions
What is dot pitch?
The distance from the centre of one pixel to the centre of the next, measured in millimetres. A smaller pitch means a finer image at the same viewing distance.
Why divide by 25.4?
Because an inch is defined as exactly 25.4 millimetres. Pixel density is counted per inch, so one inch spread over PPI pixels gives the pitch of each.
What dot pitch is good for a desktop monitor?
Roughly 0.23 mm and below looks sharp at arm's length, which is about 109 PPI or more. Phones need far less because they are held closer.
Is dot pitch the same as pixel pitch?
For LCD and OLED panels, yes. On old shadow-mask tubes the dot pitch described the phosphor triads instead, which were not identical to the addressable pixels.
Sources and last check
Information, not professional advice.