Pixel conversion
Pixels to Millimeters Converter
Convert pixels to millimeters and millimeters to pixels at any PPI. 1 inch is exactly 25.4 mm, so mm = pixels ÷ PPI × 25.4.
1200 px at 300 PPI = 101.6 mm
At 96 PPI (CSS), 1 mm = 3.7795 px · at 300 PPI, 1 mm = 11.811 px
Pixels to millimeters
Convert a full image ↗Result at 300 PPI
101.6 mm
1,200 px ÷ 300 PPI × 25.4 mm/in = 101.6 mm
- Pixels
- 1,200 px
- Inches
- 4 in
- Centimeters
- 10.16 cm
- Millimeters
- 101.6 mm
A fractional result is a measurement. For a whole-pixel print canvas, use the size-to-pixels calculator.
Millimeters to pixels
Convert a full image ↗Result at 300 PPI
1,181.102362 px
100 mm ÷ 25.4 mm/in × 300 PPI = 1,181.102362 px
- Pixels
- 1,181.102362 px
- Inches
- 3.937008 in
- Centimeters
- 10 cm
- Millimeters
- 100 mm
A fractional result is a measurement. For a whole-pixel print canvas, use the size-to-pixels calculator.
Pixels to millimeters table
The same pixel count measures a different length at each density. Values are rounded for display; the converters above use the unrounded calculation.
| Pixels | mm at 72 PPI | mm at 96 PPI | mm at 150 PPI | mm at 300 PPI |
|---|---|---|---|---|
| 1 px | 0.353 | 0.265 | 0.169 | 0.085 |
| 10 px | 3.528 | 2.646 | 1.693 | 0.847 |
| 50 px | 17.639 | 13.229 | 8.467 | 4.233 |
| 100 px | 35.278 | 26.458 | 16.933 | 8.467 |
| 200 px | 70.556 | 52.917 | 33.867 | 16.933 |
| 300 px | 105.833 | 79.375 | 50.8 | 25.4 |
| 500 px | 176.389 | 132.292 | 84.667 | 42.333 |
| 600 px | 211.667 | 158.75 | 101.6 | 50.8 |
| 1,000 px | 352.778 | 264.583 | 169.333 | 84.667 |
| 1,080 px | 381 | 285.75 | 182.88 | 91.44 |
| 1,200 px | 423.333 | 317.5 | 203.2 | 101.6 |
| 1,500 px | 529.167 | 396.875 | 254 | 127 |
| 1,920 px | 677.333 | 508 | 325.12 | 162.56 |
| 2,560 px | 903.111 | 677.333 | 433.493 | 216.747 |
| 3,000 px | 1,058.333 | 793.75 | 508 | 254 |
| 3,840 px | 1,354.667 | 1,016 | 650.24 | 325.12 |
Millimeters to pixels
Multiply the length by PPI and divide by 25.4. Round to a whole pixel only when you create a canvas; the print size calculator lets you choose nearest or upward rounding.
| Length | Pixels at 96 PPI | Pixels at 150 PPI | Pixels at 300 PPI |
|---|---|---|---|
| 1 mm | 3.78 | 5.91 | 11.81 |
| 5 mm | 18.9 | 29.53 | 59.06 |
| 10 mm | 37.8 | 59.06 | 118.11 |
| 25.4 mm | 96 | 150 | 300 |
| 50 mm | 188.98 | 295.28 | 590.55 |
| 100 mm | 377.95 | 590.55 | 1,181.1 |
| 148 mm | 559.37 | 874.02 | 1,748.03 |
| 210 mm | 793.7 | 1,240.16 | 2,480.31 |
| 297 mm | 1,122.52 | 1,753.94 | 3,507.87 |
Formula and worked example
mm = pixels ÷ PPI × 25.4
pixels = mm ÷ 25.4 × PPI
A 2400-pixel edge at 300 PPI is 2400 ÷ 300 = 8 inches, and 8 × 25.4 = 203.2 mm. In reverse, 210 mm (the width of A4) at 300 PPI is 210 ÷ 25.4 × 300 = 2,480.315 pixels, which a canvas rounds to 2480.
Screen pixels are different: CSS defines 96 CSS px per CSS inch, so 1 CSS mm is 3.7795 CSS px. That is a layout relationship, not a ruler on your display.
Questions about this conversion
How many pixels are in one millimeter?
At 300 PPI, one millimeter holds 11.811 pixels; at 150 PPI, 5.9055. In CSS layout, 1mm = 3.7795 CSS px.
How do I convert pixels to millimeters?
Divide the pixels by PPI to get inches, then multiply by 25.4. For example, 1200 px ÷ 300 PPI × 25.4 = 101.6 mm.
Why do other converters give a different answer?
The result depends entirely on the density assumed. Some tools silently use 96 (CSS) or 72; this converter shows the PPI and lets you change it.