Inch Sizes to Pixels — All Sizes

Converting a size that is not listed

The list below covers the sizes people look up most, but the arithmetic is the same for any measurement: pixels = inches × DPI. Multiply, and nothing else changes. 1.1 inches at 300 DPI is 330 pixels. 1.2 inches is 360. 1.8 inches is 540. A 2.5 × 2.5 inch square is 750 × 750. At the 96 PPI screen standard the same three lengths are 105.6, 115.2 and 172.8 pixels.

Decimals need no special handling — 1.8 is simply 1.8 × 300, not a fraction to convert first. Fractions do: turn eighths, quarters and halves into decimals before multiplying, so 8 1/2 inches is 8.5 × 300 = 2,550 pixels and 1 1/4 inches is 1.25 × 300 = 375. Rounding the decimal early is where most of the drift in a pixel count comes from.

One measurement that is not a width: a screen described as 15.6 inches is quoting its diagonal, not its edge. Multiplying 15.6 by a density gives 4,680 pixels at 300 DPI, but that is the diagonal in pixels rather than the width of the panel. To get the real edge lengths of a display you need its resolution as well — the screen PPI calculator does that, and What Is PPI? explains why the diagonal is the figure manufacturers quote.

Which density to multiply by depends on how the finished piece is looked at. Anything held in the hand wants 300 DPI; something hung on a wall and read from a metre is indistinguishable at 150 to 200; a banner read from several metres is normal at 72 or less. 300 DPI in Pixels sets out where the standard came from and when to leave it behind.

How these conversions are worked out

Every page in this index applies the same relationship: inches = pixels ÷ PPI in one direction and pixels = inches × PPI in the other. The only variable is the pixel density, which is why each page lists the answer at 72, 96, 150, 300 and 600 DPI rather than giving a single figure.

Use 96 PPI for screen and CSS work, 150 DPI for posters and drafts, and 300 DPI for anything printed and held in the hand.