How do I convert pixels to inches?

Divide the pixel count by the resolution the image will print at. 3000 pixels at 300 DPI is exactly 10 inches, and 2480 pixels at 300 DPI is 8.27 inches, which is 2480 divided by 300, a division that runs 8.266666 and never ends, rounded for display. Type the pixel dimensions and the resolution above and both figures appear, with the division spelled out underneath. One side is enough: leave the height empty and the width is converted on its own.

How many pixels are in one inch?

As many as the resolution says, which is why the field is there. At 300 DPI an inch is 300 pixels, at 150 DPI it is 150, and in a browser layout it is 96, because 96 is the CSS reference resolution. That last one is a convention rather than a measurement: 96 CSS pixels only cover a physical inch on a display that happens to run at 96 pixels per inch, and this page prints that caveat next to the answer when you enter 96, with the matching one for 72.

How many pixels do I need for an 8 by 10 inch print?

2400 x 3000 pixels at 300 DPI, which is the number this page returns when you switch the direction to size to pixels and type 8 and 10. At 150 DPI the same print needs 1200 x 1500, and the table lists the count at every common resolution. Pixel counts are whole numbers, so where the arithmetic lands between two pixels the page rounds to the nearest one and prints the unrounded count beside it.

Why does the page say a figure is rounded?

Because most divisions do not end. 2480 divided by 300 is 8.266666 and on forever, so 8.27 in is a rounded figure and the page says which value it was rounded from. When the arithmetic does end, the full value is printed and nothing is hidden: 3000 at 300 is 10 in, 1000 at 320 is 3.125 in, and 1920 at 96 is 20 in. That distinction is the point of the tool rather than a detail of it.

Is DPI the same as PPI?

For this arithmetic, yes: both mean pixels per inch, and the page treats the two words as one number. The distinction that does matter is elsewhere. A printer's DPI describes the ink dots it lays down, several of which go into one image pixel, so a 1200 DPI printer does not need a 1200 PPI image. The resolution to type here is the one your image is set to print at, which is usually 300 for a photograph.

Can I work in centimetres or millimetres?

Yes, with the unit control, in both directions. One inch is 25.4 mm exactly, so 21 x 29.7 cm at 300 DPI is 2480 x 3508 pixels, and 2480 x 3508 pixels at 300 DPI is 21.0 x 29.7 cm back again. Whichever unit you pick, the inch figure keeps its own cell and the fourth cell shows centimetres, or millimetres when that is the unit you chose.

Does this change my image?

No. It works on the numbers you type and nothing leaves the page: there is no file to choose and nothing to send anywhere. Changing the resolution stored in an image file is a job for an editor, and it moves no pixels either. If you need fewer or more pixels than you have, that is resampling, which is what an image resizer does.

Pixels to Print Size

A pixel has no physical size of its own, so "px to inches" has no single answer until a resolution is named: this page asks for that resolution and then does the division exactly. 3000 pixels at 300 DPI is 10 inches, to the digit, and the page says the figure is exact. 2480 x 3508 at 300 DPI is 8.27 x 11.69 in, or 21.0 x 29.7 cm, and the page says those are rounded, because 2480 divided by 300 runs 8.266666 and never ends. The same arithmetic runs the other way on the same screen: 8 x 10 inches at 300 DPI is 2400 x 3000 pixels, and a size in centimetres or millimetres converts at 25.4 mm to the inch. One dimension is enough, so you can leave the height empty and convert a single side. Under the answer sits the working, the assumption each figure rests on and a table of the same job at 72, 96, 150, 200, 240, 300 and 600 DPI, with your own resolution added as a row of its own.

PRINT SIZE

8.27 x 11.69 in

2480 x 3508 px at 300 DPI · 21.0 x 29.7 cm

Pixels: 2480 x 3508
DPI: 300
Inches: 8.27 x 11.69
Centimetres: 21.0 x 29.7

Width: 2480 px divided by 300 DPI is 8.27 in, which is 21.0 cm.
Height: 3508 px divided by 300 DPI is 11.69 in, which is 29.7 cm.
Rounded for display: the width runs 8.266666 inches and on, printed as 8.27 in.
Rounded for display: the height runs 11.693333 inches and on, printed as 11.69 in.
One inch is 25.4 mm exactly, so the inch, centimetre and millimetre figures are one measurement written three ways.
A pixel has no size until something prints or displays it, so every figure here follows from the 300 DPI you entered. DPI and PPI mean the same number in this arithmetic.

The numbers you have

Enter the pixel dimensions of the image and the resolution it will print at. One side is enough: leave the height empty and the width is converted on its own.

Direction

Width in pxHeight in pxResolution in DPIUnit

Common resolutions: 300 for photo printing, 150 for a poster read at arm's length, 72 or 96 for a screen mock-up. DPI and PPI mean the same number here.

The same job at every common resolution

The pixels stay as you typed them and the print size moves, which is the whole of what a resolution does.

2480 x 3508 px and 8.27 x 11.69 in, row by row
Resolution	Pixels	Inches	Centimetres
72 DPI	2480 x 3508	34.44 x 48.72	87.5 x 123.8
96 DPI	2480 x 3508	25.83 x 36.54	65.6 x 92.8
150 DPI	2480 x 3508	16.53 x 23.39	42.0 x 59.4
200 DPI	2480 x 3508	12.4 x 17.54	31.496 x 44.5516
240 DPI	2480 x 3508	10.33 x 14.62	26.2 x 37.1
300 DPI	2480 x 3508	8.27 x 11.69	21.0 x 29.7
600 DPI	2480 x 3508	4.13 x 5.85	10.5 x 14.9

Worked both ways

The three conversions below run through the very same functions as the answer above them.

2480 x 3508 at 300to inches
8.27 x 11.69
8 x 10 in at 300to pixels
2400 x 3000
Same pixels at 72to inches
34.44 x 48.72

Accuracy. Exact arithmetic: pixels divided by the resolution you enter, both directions on the same page. The resolution is yours to set because a pixel has no physical size of its own until something prints it.

Common questions

How do I convert pixels to inches?: Divide the pixel count by the resolution the image will print at. 3000 pixels at 300 DPI is exactly 10 inches, and 2480 pixels at 300 DPI is 8.27 inches, which is 2480 divided by 300, a division that runs 8.266666 and never ends, rounded for display. Type the pixel dimensions and the resolution above and both figures appear, with the division spelled out underneath. One side is enough: leave the height empty and the width is converted on its own.
How many pixels are in one inch?: As many as the resolution says, which is why the field is there. At 300 DPI an inch is 300 pixels, at 150 DPI it is 150, and in a browser layout it is 96, because 96 is the CSS reference resolution. That last one is a convention rather than a measurement: 96 CSS pixels only cover a physical inch on a display that happens to run at 96 pixels per inch, and this page prints that caveat next to the answer when you enter 96, with the matching one for 72.
How many pixels do I need for an 8 by 10 inch print?: 2400 x 3000 pixels at 300 DPI, which is the number this page returns when you switch the direction to size to pixels and type 8 and 10. At 150 DPI the same print needs 1200 x 1500, and the table lists the count at every common resolution. Pixel counts are whole numbers, so where the arithmetic lands between two pixels the page rounds to the nearest one and prints the unrounded count beside it.
Why does the page say a figure is rounded?: Because most divisions do not end. 2480 divided by 300 is 8.266666 and on forever, so 8.27 in is a rounded figure and the page says which value it was rounded from. When the arithmetic does end, the full value is printed and nothing is hidden: 3000 at 300 is 10 in, 1000 at 320 is 3.125 in, and 1920 at 96 is 20 in. That distinction is the point of the tool rather than a detail of it.
Is DPI the same as PPI?: For this arithmetic, yes: both mean pixels per inch, and the page treats the two words as one number. The distinction that does matter is elsewhere. A printer's DPI describes the ink dots it lays down, several of which go into one image pixel, so a 1200 DPI printer does not need a 1200 PPI image. The resolution to type here is the one your image is set to print at, which is usually 300 for a photograph.
Can I work in centimetres or millimetres?: Yes, with the unit control, in both directions. One inch is 25.4 mm exactly, so 21 x 29.7 cm at 300 DPI is 2480 x 3508 pixels, and 2480 x 3508 pixels at 300 DPI is 21.0 x 29.7 cm back again. Whichever unit you pick, the inch figure keeps its own cell and the fourth cell shows centimetres, or millimetres when that is the unit you chose.
Does this change my image?: No. It works on the numbers you type and nothing leaves the page: there is no file to choose and nothing to send anywhere. Changing the resolution stored in an image file is a job for an editor, and it moves no pixels either. If you need fewer or more pixels than you have, that is resampling, which is what an image resizer does.

Exact arithmetic: pixels divided by the resolution you enter, both directions on the same page. The resolution is yours to set because a pixel has no physical size of its own until something prints it.