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DPI to PPI Converter

PhotographyImage Size and Print
Resolution measured
Pixels per inch (PPI) —
Pixels per centimetre
—
Print size (inches)
—
Print size (cm)
—
Megapixels
—

For a digital image, the DPI number stored in the file is a pixels-per-inch value, so 300 DPI equals 300 PPI. What changes is the print size: divide each pixel dimension by the PPI. A 3000 × 2400 px photo at 300 PPI prints at 10 × 8 inches, or 25.4 × 20.32 cm.

About this tool

Print shops ask for 300 DPI, camera files say 72 DPI, and image editors talk about PPI. For a digital file these are the same number: the resolution tag tells software how many pixels to place in each inch of paper. This converter takes that value, per inch or per centimetre, plus the image's pixel width and height, and returns the pixels per inch, pixels per centimetre, the print size in inches and centimetres, and the megapixel count, with the working shown. It does not describe a printer's own ink-dot density: an inkjet rated at 1440 or 2880 dpi lays many ink droplets per image pixel, and that figure cannot be converted to PPI.

How to use it

  1. Enter the resolution

    Type the DPI value from the file properties or the print brief, for example 300.

  2. Choose per inch or per centimetre

    Pick Per centimetre if your software reports dots per cm, as some European layout tools do.

  3. Add the pixel dimensions

    Enter the image width and height in pixels to see how large it prints at that resolution.

  4. Read the print size

    The results list the size in inches and centimetres, the pixels per cm and the steps behind each number.

Examples

300 DPI, 3000 × 2400 px

Resolution (DPI)
300
Resolution measured
Per inch
Image width
3000
Image height
2400

Result Pixels per inch (PPI): 300
Pixels per centimetre: 118.11
Print size (inches): 10 × 8 in
Print size (cm): 25.4 × 20.32 cm
Megapixels: 7.2

  1. PPI = DPI = 300 (a file stores one resolution value, read per inch)
  2. Pixels per cm = 300 ÷ 2.54 = 118.11
  3. Print width = 3000 px ÷ 300 = 10 in = 25.4 cm
  4. Print height = 2400 px ÷ 300 = 8 in = 20.32 cm

A 7.2-megapixel file tagged 300 DPI prints at exactly 10 × 8 inches at full photo quality.

72 DPI, 1920 × 1080 px

Resolution (DPI)
72
Resolution measured
Per inch
Image width
1920
Image height
1080

Result Pixels per inch (PPI): 72
Pixels per centimetre: 28.35
Print size (inches): 26.67 × 15 in
Print size (cm): 67.73 × 38.1 cm
Megapixels: 2.07

  1. PPI = DPI = 72 (a file stores one resolution value, read per inch)
  2. Pixels per cm = 72 ÷ 2.54 = 28.35
  3. Print width = 1920 px ÷ 72 = 26.67 in = 67.73 cm
  4. Print height = 1080 px ÷ 72 = 15 in = 38.1 cm

A full-HD frame tagged 72 DPI would print almost 27 inches wide, but at 72 pixels per inch it looks coarse up close.

118.11 dots/cm, A4 at 300 PPI

Resolution (DPI)
118.11
Resolution measured
Per centimetre
Image width
2480
Image height
3508

Result Pixels per inch (PPI): 300
Pixels per centimetre: 118.11
Print size (inches): 8.27 × 11.69 in
Print size (cm): 21 × 29.7 cm
Megapixels: 8.7

  1. PPI = 118.11 dots/cm × 2.54 = 300
  2. Pixels per cm = 300 ÷ 2.54 = 118.11
  3. Print width = 2480 px ÷ 300 = 8.27 in = 21 cm
  4. Print height = 3508 px ÷ 300 = 11.69 in = 29.7 cm

2480 × 3508 px is the standard A4 page at 300 PPI; entering the metric resolution gives the same 21 × 29.7 cm sheet.

How it is calculated

PPI = DPI (per inch) or dots per cm × 2.54; print width = pixel width ÷ PPI; print height = pixel height ÷ PPI

PPI
pixels per inch of the printed image
DPI
the resolution value stored in the file or requested by the printer
2.54
centimetres in one inch, an exact definition

Image formats such as JPEG, PNG and TIFF store a single resolution field. Software labels it DPI or PPI interchangeably, and it only sets how many pixels fill one inch when printed; it does not change the pixels themselves. Dividing the pixel count by that density gives the physical size. A metric resolution is multiplied by 2.54 to get the per-inch figure, and inch sizes are multiplied by 2.54 for centimetres.

When not to use it

  • Do not use it to convert a printer's rated ink-dot resolution such as 2880 dpi into image pixels.
  • It does not judge screen sharpness; monitor pixel density depends on panel size and resolution instead.
  • Halftone screen rulings in lines per inch for offset printing need a different rule of thumb.

Common mistakes

  • Changing a file from 72 to 300 DPI and expecting more detail; only the print size shrinks.
  • Treating 72 DPI as low quality on screen, where the tag is ignored entirely.
  • Upscaling a small image to hit 300 PPI, which adds pixels but no real detail.
  • Mixing up dots per centimetre with dots per inch when reading metric software settings.

Frequently asked questions

Are DPI and PPI the same thing?

For a digital image file, yes in practice: the single resolution tag is read as pixels per inch, whatever the software calls it. Strictly, DPI describes ink or toner dots a printer lays down, and PPI describes image pixels per inch. A printer may use many ink dots to render one pixel.

What resolution do photo labs want?

Most labs and print services ask for about 300 PPI at the final print size for prints viewed at arm's length. Large posters and banners viewed from a few metres away often look fine at 150 PPI or lower, because the eye cannot resolve finer detail at that distance.

Why do so many images say 72 DPI?

72 is a historical default from early Mac displays and many cameras or export tools still write it. On screen the tag has no effect; a browser shows the pixels as they are. It only matters once you print, where 72 PPI would make a very large but soft print.

Does raising the DPI improve image quality?

No. Changing the resolution tag without resampling keeps every pixel and only makes the print smaller. A 3000 px wide image is 41.67 inches wide at 72 PPI and 10 inches wide at 300 PPI, with identical detail in both cases.

How many pixels do I need for an A4 print at 300 PPI?

A4 is 210 × 297 mm, or about 8.27 × 11.69 inches. Multiplying by 300 gives roughly 2480 × 3508 pixels, which is about 8.7 megapixels. Enter those numbers above to confirm the 21 × 29.7 cm result.

How do I convert dots per centimetre to DPI?

Multiply by 2.54, the number of centimetres in an inch. 118.11 dots per cm is 300 per inch, and 47.24 dots per cm is 120 per inch. Choose Per centimetre in the converter to have it done for you.

Cite this tool

Using this tool in an assignment, article or report? Copy a citation, or a link for your website.

APA

Tools Directory Editorial Team. (2026, October 20). DPI to PPI Converter. Tools Directory. Retrieved October 27, 2026, from https://tools.milunir.com/photography/image-size-and-print/dpi-to-ppi-converter/

MLA

Tools Directory Editorial Team. “DPI to PPI Converter.” Tools Directory, 20 Oct. 2026, https://tools.milunir.com/photography/image-size-and-print/dpi-to-ppi-converter/. Accessed 27 Oct. 2026.

Chicago

Tools Directory Editorial Team. “DPI to PPI Converter.” Tools Directory. Last modified October 20, 2026. Accessed October 27, 2026. https://tools.milunir.com/photography/image-size-and-print/dpi-to-ppi-converter/.

Link<a href="https://tools.milunir.com/photography/image-size-and-print/dpi-to-ppi-converter/">DPI to PPI Converter – Tools Directory</a>