Pixels · Inches · DPI

DPI Calculator

Enter any two values — the calculator finds the third. See exactly how big your image will print at any DPI.

Free Instant No signup

This is a calculator, not a DPI changer. It does the arithmetic between pixels, inches, and DPI. It never opens or rewrites a file. To set the density tag on a JPG or PNG, use the Image DPI Changer.

Pixels Calculated

Width (px) Height (px)

DPI Calculated

DPI

Print size Calculated

Print Width (in) Print Height (in)

3000 × 2000 px at 300 DPI → 10.00 × 6.67 in (25.4 × 16.9 cm)

Solving for print size — inches = pixels ÷ DPI. Change any two groups to recalculate the third.

Print size at common DPI

At 72 DPI	At 150 DPI	At 200 DPI	At 300 DPI	At 600 DPI
41.67 × 27.78 in	20.00 × 13.33 in	15.00 × 10.00 in	10.00 × 6.67 in	5.00 × 3.33 in

Common print sizes

Pixels needed to print these standard sizes without upscaling. 300 DPI is photo-lab quality; 150 DPI is the usual floor for large-format work viewed from a distance.

Print Size	Pixels needed at 300 DPI	Pixels needed at 150 DPI
4×6 in	1200×1800	600×900
5×7 in	1500×2100	750×1050
8×10 in	2400×3000	1200×1500
8.5×11 in (Letter)	2550×3300	1275×1650
11×14 in	3300×4200	1650×2100
A4 (8.27×11.69 in)	2481×3507	1241×1754

Plug any of those pixel counts into the calculator with a different DPI to see the print size change. A 2400×3000 px file is an 8×10 at 300 DPI and a 16×20 at 150 DPI — same pixels, twice the paper.

The DPI formula

Three numbers, one relationship. Rearrange to solve for whichever you do not have:

DPI = pixels ÷ inches
inches = pixels ÷ DPI
pixels = inches × DPI

A 3000 px-wide photo printed 10 inches wide is 300 DPI. The same pixels printed 41.67 inches wide are 72 DPI. Nothing about the picture changed except how tightly the printer is asked to pack those pixels.

Width and height use the same DPI. If a file is 3000×2000 px at 300 DPI, it prints 10×6.67 in. Centimetres are inches × 2.54.

This arithmetic is what print shops mean by “enough resolution.” A 1200×1800 px image is a legitimate 4×6 at 300 DPI and is not a legitimate 16×24 at 300 DPI, tag or no tag. The Image DPI Changer rewrites the density tag; it cannot invent pixels. Use this calculator first if you are not sure the file covers the print.

Common DPI values and when to use them

The number is a convention, not a quality slider. Pick the density the job actually needs, then confirm the pixel count covers the print at that density.

DPI	Typical use	3000 × 2000 px prints at
72	Screen / web (legacy Mac)	41.67 × 27.78 in
150	Draft / large format	20.00 × 13.33 in
200	Newsprint	15.00 × 10.00 in
300	Photo quality	10.00 × 6.67 in
600	Fine art / medical / line art	5.00 × 3.33 in

72 DPI — screen

The old Macintosh screen convention. Web exporters, screenshots, and AI image tools still write 72, or write nothing and let the viewer assume 72. Screens ignore the tag and paint pixels, so 72 is fine for anything that stays on a monitor. It becomes a problem only when a print workflow reads the file.

150 DPI — draft / large format

The usual floor for posters, banners, and booth graphics viewed from a few feet. A 24-inch-wide poster at 150 DPI needs 3600 px across. 300 DPI on that same poster would demand 7200 px and a much larger file for detail nobody can see from the aisle.

200 DPI — newsprint

Newspapers and uncoated stock often specify around 200 DPI because the paper and the press cannot hold a finer halftone. Sending 300 is harmless if the pixels are there; sending 72 on a news photo that will print 8 inches wide is not.

300 DPI — photo quality

The industry habit for photo labs, magazines, journals, ID portals, Amazon KDP, and Etsy printables. Dense enough that a 150-line halftone and normal viewing distance hide the pixel grid. Preflight software almost always checks this number. See Convert Image to 300 DPI to rewrite the tag once the pixel count already covers the print.

600 DPI — fine art / medical

Line art, hairline charts, and some medical or archival scans. Author guidelines often ask 600 for figures that are not photographs. A 600 tag on a soft photo does not add detail — it just claims a smaller print. Use 600 when the original actually has that many samples per inch, or when a portal will reject 300 on a chart.

If you need the stored tag on a real file, not the arithmetic, use the DPI Checker. For the vocabulary mix-up with PPI, see DPI vs PPI.

Frequently asked questions

How do I calculate DPI from pixels and inches?

DPI = pixels ÷ inches. A 3000-pixel-wide image that should print 10 inches wide is 300 DPI. Enter any two of pixels, inches, and DPI in the calculator; it fills the third.

What is 8.5 x 11 in pixels at 300 DPI?

2550 × 3300 pixels. Pixels = inches × DPI, so 8.5 × 300 = 2550 and 11 × 300 = 3300. That is US Letter at photo-quality density.

How many pixels do I need for a 4x6 print at 300 DPI?

1200 × 1800 pixels. At 150 DPI the same 4×6 print only needs 600 × 900 pixels, which is acceptable for a snapshot viewed at arm's length but not for a lab print.

What DPI do I need for a large print?

150 DPI is the usual floor for posters and banners viewed from a few feet. 200 is common for newsprint. 300 is more than you need on a 24×36 inch poster unless someone will inspect it up close. Divide pixel width by print width in inches to get the DPI you actually have.

Is 72 DPI good enough for web?

Yes. Screens ignore the DPI tag and paint pixels. 72 is a legacy Macintosh screen convention. A 72 DPI file and a 300 DPI file with the same pixel count look identical on a monitor. 72 only becomes a problem when a print workflow reads the tag.

How do I convert inches to pixels?

Pixels = inches × DPI. An 8×10 inch print at 300 DPI needs 2400×3000 pixels. Enter the print size and DPI in the calculator; it fills the pixel fields.

What size image do I need for an A4 print at 300 DPI?

A4 is 8.27 × 11.69 inches, so 2481 × 3507 pixels at 300 DPI. At 150 DPI you need 1241 × 1754 pixels.

Does this DPI calculator change my image file?

No. This page only does the arithmetic between pixels, inches, and DPI. It never opens or rewrites a file. To set the density tag on a JPG or PNG, use the Image DPI Changer on the homepage or Convert Image to 300 DPI.