Pixels to Inches Converter
Convert pixels to inches, or inches to pixels, at any DPI. Works in centimetres and millimetres too, for a single length or a width × height, and tells you how big a photo will print.
- 1Enter a size
- 2Pick the DPI
- 3Read the result
1Size
Changing the unit converts what's in the boxes. Changing the DPI keeps the numbers you typed and recalculates the rest.
2Resolution (DPI / PPI)
300 for photo prints you hold in your hand, 150 for posters seen from a few feet away, 96 for CSS and web layouts, 72 is an old screen default. Type any value for your printer or screen.
3Result
–
| Unit | Width | Height |
|---|
Pixels are rounded to the nearest whole pixel (the exact value is shown when it isn't whole). Inches and centimetres are rounded to 3 decimals, millimetres to 2.
+Or load an image to read its pixel size
| DPI | Inches | Centimetres |
|---|
Common print sizes in pixels
Pixel width × height for each size, worked out by this page from the paper's real dimensions. Portrait orientation; swap the numbers for landscape. Pick a row to load it into the converter. On a phone, swipe the table sideways for 150 and 72 DPI.
| Size | 300 DPI | 150 DPI | 72 DPI |
|---|
How to convert pixels and inches
A pixel has no fixed physical size. It only gets one when you decide how many pixels go into each inch: that number is the DPI (dots per inch) or PPI (pixels per inch). Once you pick it, the maths is one step:
pixels = inches × DPI
inches = pixels ÷ DPI
- A 4 × 6 in photo at 300 DPI needs 1200 × 1800 px.
- An image 3000 px wide prints 10 in wide at 300 DPI, or 20 in at 150 DPI.
- For centimetres, divide by 2.54 first (1 in = 2.54 cm exactly). For millimetres, divide by 25.4.
96 pixels per inch on the web, any DPI in print
CSS defines its units so that 1in = 96px, and 1px = 1/96 in (W3C CSS Values and Units Level 4, §6.2 Absolute lengths). That's why most converters say an inch is 96 pixels.
That CSS pixel is a "reference pixel", not a dot on your screen. On screens, browsers tie the units to the pixel, so a CSS inch is 96 CSS pixels but usually not a real inch you could measure with a ruler: a phone may draw each CSS pixel with 2 or 3 device pixels. When printing, the spec recommends tying them to physical units instead, so a CSS inch prints as an actual inch.
Printing a photo is different again. The pixels in the file are fixed, and the DPI you print at decides the size on paper. The DPI number stored inside an image file is just a label: changing it doesn't add or remove pixels or make the picture sharper. It only changes the size an app suggests when you print.
Which DPI to use
- 300 DPI: the usual target for photos, flyers and anything read at arm's length.
- 150 to 200 DPI: often enough for posters and banners seen from a few feet away.
- 96: CSS pixels in web design. 72: an old Mac screen standard that many apps still write as a default.
- Your printer or print shop may ask for something specific. Use their number in the custom box.
FAQ
How many pixels are in an inch?
It depends on the resolution you choose. In CSS and web design, an inch is 96 pixels by definition. For print, it's whatever DPI you print at: 300 pixels per inch at 300 DPI, 150 at 150 DPI. Older software often assumes 72.
How do I convert inches to pixels?
Multiply the inches by the DPI. A 4 × 6 in print at 300 DPI is 4 × 300 by 6 × 300, which is 1200 × 1800 pixels. Type the size above, choose inches, and pick the DPI.
How do I convert pixels to inches?
Divide the pixels by the DPI. An image 3000 pixels wide is 10 inches wide at 300 DPI. Load the image above to see its print size at several DPIs at once.
What is 8.5 x 11 in pixels?
US Letter (8.5 × 11 in) is 2550 × 3300 pixels at 300 DPI, 1275 × 1650 at 150 DPI, 816 × 1056 at 96 DPI and 612 × 792 at 72 DPI.
How many pixels is A4?
A4 is 210 × 297 mm, which is about 2480 × 3508 pixels at 300 DPI (the exact values are 2480.3 × 3507.9, rounded to whole pixels).
Is 1 inch always 96 pixels?
Only in CSS. The W3C defines a CSS inch as 96 CSS pixels, but a CSS pixel isn't the same as a physical screen pixel, and print size depends on the DPI you print at. A photo has no inch size until you choose a DPI.
Does changing the DPI make an image sharper?
No. Changing the DPI setting without resizing keeps every pixel and only changes the suggested print size. To print bigger at the same quality you need more pixels to start with.
What's the difference between DPI and PPI?
PPI counts the pixels per inch in an image or on a screen. DPI originally counts the ink dots a printer lays down per inch. In everyday use, including image-size dialogs, people use DPI to mean PPI, and this converter treats them the same.
How do I set the size in Photoshop?
In Image › Image Size, turn off Resample, then type the resolution or the inches: the pixel count stays the same and only the print size changes. Turn Resample on only when you want to add or remove pixels.