DPI Calculator (Print Size and Resolution)
Work out print size from pixels and DPI, the DPI of a print from its pixels and size, or the pixels needed for a print size, in inches, cm or mm.
Changing the DPI value of a file does not add or remove pixels; it only changes how large the image prints. 1 in = 2.54 cm = 25.4 mm.
| DPI | Print size (in) | Typical use |
|---|---|---|
| 72 | 41.67 × 33.33 in | old screen convention |
| 96 | 31.25 × 25 in | Windows screen default |
| 150 | 20 × 16 in | posters, banners |
| 200 | 15 × 12 in | large photos |
| 240 | 12.5 × 10 in | inkjet photo |
| 300 | 10 × 8 in | photo lab, magazines |
| 600 | 5 × 4 in | line art, scans |
DPI (dots per inch) — for digital images really PPI, pixels per inch — links three numbers: an image's pixels, its print size and its resolution. Know any two and this calculator gives the third: how large a photo prints at 300 DPI, what DPI a file has at a given print size, or how many pixels a poster or A4 page needs. Sizes can be in inches, centimeters or millimeters, and a table shows the result at the common resolutions from 72 to 600 DPI.
How to use this tool
- Choose what to calculate: print size, DPI or pixels needed.
- Enter the two known values — pixels, DPI and/or the print size.
- Pick inches, centimeters or millimeters for the print size.
- Read the answer and compare other resolutions in the table.
Formula
print size = pixels ÷ DPI · DPI = pixels ÷ print size (in inches) · pixels = print size (in inches) × DPI
Centimeters are divided by 2.54 and millimeters by 25.4 to get inches first. When width and height give different DPI, the image and the paper have different shapes.
Example
A 3000 × 2400 px image at 300 DPI prints at 3000 ÷ 300 = 10 × 8 in (25.4 × 20.32 cm). An A4 page (210 × 297 mm) at 300 DPI needs 210 ÷ 25.4 × 300 = 2480 by 3508 px — 2480 × 3508 px, about 8.7 megapixels.
Frequently asked questions
Does changing DPI make my image sharper?
No. Setting 300 DPI instead of 72 DPI in a file keeps exactly the same pixels; it only tells the printer to pack them more tightly, so the print gets smaller. Sharpness depends on pixels per inch of paper.
What is the difference between DPI and PPI?
PPI counts image pixels per inch; DPI strictly counts printer ink dots, which are much finer. In print-size calculations like this one the two words mean the same thing.
Why do screens use 72 or 96 DPI?
Those are old conventions from early Mac (72) and Windows (96) displays. Screens show images pixel for pixel, so the DPI value stored in a file has no effect on screen.
Last updated:
Page address with these inputs: https://kakao.mobile/tools/dpi-calculator/
Cite or embed this tool
kakaoCalc. (2026, November 8). DPI Calculator (Print Size and Resolution). https://kakao.mobile/tools/dpi-calculator/
“DPI Calculator (Print Size and Resolution).” kakaoCalc, 8 Nov. 2026, kakao.mobile/tools/dpi-calculator/.
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