How many pixels is 8.5 x 11 inches?

At 300 DPI, a US Letter page (8.5 × 11 in) is 2550 × 3300 pixels. At 150 DPI it is 1275 × 1650, and at 72 DPI it is 612 × 792.

What size is a 4x6 photo in pixels?

A 4 × 6 inch photo needs 1200 × 1800 pixels at 300 DPI (4 × 300 by 6 × 300). At 150 DPI it is 600 × 900 pixels.

How do I convert pixels to inches?

Divide the pixels by the DPI (dots or pixels per inch). 3000 pixels printed at 300 DPI make 10 inches; the same 3000 pixels at 150 DPI make 20 inches.

How many pixels are in an inch?

There is no fixed number: it depends on the resolution you print or display at. On the web, CSS defines 1 inch as exactly 96 CSS pixels, but a physical screen may show more or fewer device pixels per inch.

Is DPI the same as PPI?

Strictly, PPI counts pixels in an image or screen and DPI counts the dots a printer lays down. This calculator uses both terms for the same thing: how many image pixels fill one inch.

Inches to Pixels Converter (DPI and Paper Sizes)

Pixels = inches × DPI. Pick a paper size or type your own, choose a resolution, and read the pixel size. The second panel converts pixels back to inches and centimeters.

8.5 x 11 in pixels

US Letter paper is 8.5 × 11 inches (216 × 279 mm in this paper size summary). Its pixel size depends on the resolution:

Resolution	8.5 × 11 in in pixels
72 DPI	612 × 792
96 DPI	816 × 1056
150 DPI	1275 × 1650
300 DPI	2550 × 3300
600 DPI	5100 × 6600

Each row is the page size multiplied by the resolution: at 300 DPI that is 8.5 × 300 = 2550 by 11 × 300 = 3300 pixels. Doubling the DPI doubles both sides, so 600 DPI gives 5100 × 6600.

Photo print sizes in pixels

Print size	150 DPI	300 DPI
4 × 6 in	600 × 900	1200 × 1800
5 × 7 in	750 × 1050	1500 × 2100
8 × 10 in	1200 × 1500	2400 × 3000
11 × 14 in	1650 × 2100	3300 × 4200

Not sure whether your file is big enough? Drop it into the image resolution checker; it shows the largest print size at 300 and 150 DPI.

A4 and other metric sizes

A-series sizes are set in millimeters by ISO 216 (see this summary of ISO paper sizes): A4 is 210 × 297 mm and A5 is 148 × 210 mm. Converted with 25.4 mm to the inch, A4 is 2480 × 3508 pixels at 300 DPI and 1240 × 1754 at 150 DPI.

Why 96 pixels per inch on the web?

CSS defines an inch as exactly 96 CSS pixels (W3C). That is a layout unit, not a promise about your screen. On a high-density (HiDPI or Retina) display the device pixel ratio is typically 2, so each CSS pixel is drawn with a 2 × 2 block of device pixels. Check yours with What's My Screen Resolution, or work out shapes with the aspect ratio calculator.

Frequently asked questions

How many pixels is 8.5 x 11 inches?: At 300 DPI, a US Letter page (8.5 × 11 in) is 2550 × 3300 pixels. At 150 DPI it is 1275 × 1650, and at 72 DPI it is 612 × 792.
What size is a 4x6 photo in pixels?: A 4 × 6 inch photo needs 1200 × 1800 pixels at 300 DPI (4 × 300 by 6 × 300). At 150 DPI it is 600 × 900 pixels.
How do I convert pixels to inches?: Divide the pixels by the DPI (dots or pixels per inch). 3000 pixels printed at 300 DPI make 10 inches; the same 3000 pixels at 150 DPI make 20 inches.
How many pixels are in an inch?: There is no fixed number: it depends on the resolution you print or display at. On the web, CSS defines 1 inch as exactly 96 CSS pixels, but a physical screen may show more or fewer device pixels per inch.
Is DPI the same as PPI?: Strictly, PPI counts pixels in an image or screen and DPI counts the dots a printer lays down. This calculator uses both terms for the same thing: how many image pixels fill one inch.

Sources

NIST Guide to the SI, Appendix B.9: factors for units listed by kind of quantity (inch = 2.54 × 10⁻² m exactly), National Institute of Standards and Technology
International standard paper sizes (ISO 216 A, B and C series), Markus Kuhn, University of Cambridge Computer Laboratory
CSS Values and Units Module Level 3: absolute lengths (1in = 96px), W3C