Convert pixels to inches at any DPI

Pixels turn into inches with a single division: the pixel count divided by the DPI. A file 1,080 pixels wide measures 11.25 inches on screen at 96 DPI and 3.6 inches on paper at 300 DPI. The rate of 96 pixels per inch is the one the CSS specification assigns to the screen [1].

One pixel count therefore describes two entirely different physical sizes, and only the DPI (dots per inch) settles which of them you mean. That is why the density field sits next to the pixel field.

The conversion helps when you hold a finished file and want to know how large it will come out on paper, or when a resolution has landed on your desk and you are checking whether it covers the size ordered.

Below you will find a table of 43 values at three densities, an explanation of Windows display scaling, a breakdown of figures such as 1,080, 2,550 and 851 together with where each comes from, a table of print aspect ratios, and the largest formats camera sensors will yield. The journey the other way is handled by the inches to pixels converter.

The formula holds one operation: inches = pixels ÷ DPI. It is the reverse of the multiplication that turns inches into pixels.

Take a file of 2,550 × 3,300 pixels at 300 DPI: the width is 2,550 ÷ 300 = 8.5 inches and the height is 3,300 ÷ 300 = 11 inches. That is a Letter sheet exactly. Shown on screen at 96 DPI the same file would span 26.56 × 34.38 inches, far more than fits on a monitor.

Hence the rule for reading the result: the higher the DPI you enter, the smaller the physical size the same pixel count produces, because those pixels pack together more tightly.

If you would rather have the answer in metric units, the same file is handled by the pixels to centimeters converter and the pixels to millimeters converter. Type on that same page is measured in typographic points, and one point is exactly 1/72 of an inch, so 96 pixels come to a round 72 points. That figure comes from the pixels to points converter. Above a hundred inches American orders switch to feet: 18,000 pixels at 150 DPI is 120 inches, or 10 feet. That form comes from the pixels to feet converter.

The figure of 96 came out of typography. Microsoft sets it out in its own Win32 documentation: a 72-point font is by definition one logical inch tall, and Windows has long converted a logical inch into 96 pixels. That is why a 12-point font occupies 16 pixels on screen [2].

A logical inch is therefore a unit of calculation, which the system converts into pixels according to its own setting. The same documentation says plainly that “pixels per logical inch” would be the more accurate term for displays, and that the abbreviation DPI carried over from printing, where dots of ink really do land on paper.

The consequence shows up in the scaling settings. Windows lists three standard values: 100% corresponds to 96 DPI, 125% to 120 DPI, and 150% to 144 DPI. At 150% scaling a single device-independent pixel occupies one and a half physical pixels, so an element written as width: 1in takes up 144 physical pixels [2].

The result in the 96 DPI column therefore describes a measurement in logical inches. The distance you would measure with a ruler against the glass follows the real density of the screen, its resolution divided by its diagonal.