Enter the size in pixels and the resolution (PPI/DPI) of the digital image into the calculator to determine the size in millimeters. This calculator can also evaluate any of the variables given the others are known.

Pixel to mm Calculator

Pixels only convert to real-world mm when you assume a pixel density (PPI/DPI). Choose a common intent below.

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Enter Pixels or a physical Size. In Print mode, provide any two fields to solve the third.

px

Pixel To Mm Formula

The following formula is used to calculate the conversion from pixels to millimeters.

MM = P / (DPI / 25.4)

Variables:

  • MM is the size in millimeters
  • P is the size in pixels
  • DPI is the resolution in dots per inch (printing) or pixels per inch (often written as PPI for screens)

To calculate the size in millimeters, first divide the size in pixels by the resolution (per inch) to get the size in inches. Then, multiply by 25.4 (the number of millimeters in an inch) to convert inches to millimeters.

Pixels to Millimeters Conversion Table (Common DPIs: 72, 96, 150, 300, 600)
Pixels (px) Millimeters (mm) @ 72 DPI Millimeters (mm) @ 96 DPI Millimeters (mm) @ 150 DPI Millimeters (mm) @ 300 DPI Millimeters (mm) @ 600 DPI
165.644.232.711.350.68
248.476.354.062.031.02
3211.298.475.422.711.35
4816.9312.708.134.062.03
6422.5816.9310.845.422.71
7225.4019.0512.196.103.05
9633.8725.4016.268.134.06
12042.3331.7520.3210.165.08
12845.1633.8721.6710.845.42
15052.9239.6925.4012.706.35
19267.7350.8032.5116.268.13
25690.4967.7343.3521.6710.84
300105.8379.3850.8025.4012.70
360127.0095.2560.9630.4815.24
400141.11105.8367.7333.8716.93
480169.33127.0081.2840.6420.32
600211.67158.75101.6050.8025.40
720254.00190.50121.9260.9630.48
960338.67254.00162.5681.2840.64
1200423.33317.50203.20101.6050.80
*Assumes square pixels. Formula: mm = px × 25.4 / DPI. Common DPIs shown: 72, 96, 150, 300, 600. Note: 1 dpcm = 2.54 dpi.

What is a Pixel To Mm?

Pixel to mm is a conversion used in digital imaging to translate pixel units into physical millimeters. This conversion is crucial in graphic design, printing, and other fields where the physical size of an image or object is important. The conversion rate is not fixed and depends on the resolution (pixels per inch, often written as PPI; sometimes informally labeled as DPI). Higher resolution values result in more pixels per millimeter, leading to a higher level of detail in the printed image.

How to Calculate Pixel To Mm?

The following steps outline how to calculate the Pixel To Mm using the formula: MM = P / (DPI / 25.4).


  1. First, determine the size in pixels (P).
  2. Next, determine the resolution of the digital image (DPI).
  3. Next, calculate the value of DPI divided by 25.4.
  4. Finally, divide the size in pixels (P) by the value obtained in the previous step to calculate the size in millimeters (MM).
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Size in pixels (P) = 800

Resolution of the digital image (DPI) = 300