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Image Resolution Calculator

PhotographyImage Size and Print

300 is the usual target for photo prints; 150 suits posters seen from a distance.

Megapixels —
Print size (inches)
—
Print size (cm)
—
Total pixels
—
Aspect ratio
—
Print quality at this PPI
—

Divide each pixel dimension by the print resolution in pixels per inch to get the print size, and multiply width by height for the pixel count. A 3000 × 2400 pixel image is 7.2 megapixels and prints at 10 × 8 inches (25.4 × 20.3 cm) at 300 PPI, the usual standard for photo prints.

About this tool

Photographers sending files to a lab, designers checking a client's logo, and anyone ordering a canvas need to know how big an image can print before it turns soft. Enter the width and height in pixels and the resolution you plan to print at. The calculator returns the megapixel count, the print size in inches and centimetres, the total pixel count, the reduced aspect ratio and a plain rating of how the chosen PPI holds up at viewing distance. The figures assume the file is printed at its native pixel count; resampling software can enlarge a file, but it invents detail rather than recovering it, so a 2 MP image upscaled to 300 PPI will not look like a 24 MP original.

How to use it

  1. Enter the pixel dimensions

    Type the width and height in pixels, as shown in your editor or the file's properties.

  2. Set the print resolution

    Use 300 PPI for photo prints, 200–240 for books held in hand, and 100–150 for posters and banners.

  3. Read the print size

    Megapixels head the results, followed by the size in inches and centimetres, the aspect ratio and a quality rating.

Examples

An 8 × 10 photo print

Image width
3000
Image height
2400
Print resolution
300

Result Megapixels: 7.2
Print size (inches): 10 × 8 in
Print size (cm): 25.4 × 20.3 cm
Total pixels: 7,200,000
Aspect ratio: 5:4
Print quality at this PPI: Photo-quality print (300 PPI or more)

  1. Megapixels = 3000 × 2400 ÷ 1,000,000 = 7.2
  2. Print width = 3000 ÷ 300 = 10 in
  3. Print height = 2400 ÷ 300 = 8 in
  4. Centimetres = inches × 2.54

A 7.2-megapixel file is exactly enough for a 10 × 8 inch print at the 300 PPI photo labs ask for.

24 MP camera, 6000 × 4000

Image width
6000
Image height
4000
Print resolution
300

Result Megapixels: 24
Print size (inches): 20 × 13.33 in
Print size (cm): 50.8 × 33.9 cm
Total pixels: 24,000,000
Aspect ratio: 3:2
Print quality at this PPI: Photo-quality print (300 PPI or more)

  1. Megapixels = 6000 × 4000 ÷ 1,000,000 = 24
  2. Print width = 6000 ÷ 300 = 20 in
  3. Print height = 4000 ÷ 300 = 13.33 in
  4. Centimetres = inches × 2.54

A typical 3:2 sensor file prints at 20 × 13.33 inches before any upscaling.

A 1080p frame as a poster

Image width
1920
Image height
1080
Print resolution
100

Result Megapixels: 2.07
Print size (inches): 19.2 × 10.8 in
Print size (cm): 48.8 × 27.4 cm
Total pixels: 2,073,600
Aspect ratio: 16:9
Print quality at this PPI: Screen or distant viewing only

  1. Megapixels = 1920 × 1080 ÷ 1,000,000 = 2.07
  2. Print width = 1920 ÷ 100 = 19.2 in
  3. Print height = 1080 ÷ 100 = 10.8 in
  4. Centimetres = inches × 2.54

A video still holds about 2 megapixels, so a large print only works at low PPI and from a distance.

How it is calculated

print width = W ÷ PPI; print height = H ÷ PPI; megapixels = W × H ÷ 1,000,000; cm = in × 2.54

W
image width in pixels
H
image height in pixels
PPI
pixels per inch laid down on paper

Resolution links pixels to physical length: at 300 PPI, every inch of paper uses 300 pixels, so a 3000-pixel side covers 10 inches. Centimetres use the exact 2.54 cm per inch. The aspect ratio is the width and height divided by their greatest common divisor, so 6000 × 4000 reduces to 3:2. Quality bands follow common lab practice: 300 PPI or more for close inspection, 200–299 good, 150–199 acceptable at arm's length, and below that for distant viewing.

When not to use it

  • It does not measure sharpness, so a blurred 24 MP file still prints blurred.
  • Screen display sizes depend on the device's own pixel density, not on a PPI you type here.
  • Vector artwork has no fixed pixel count and prints at any size.

Common mistakes

  • Treating the DPI tag stored in a file as its quality; only the pixel count matters for print size.
  • Confusing printer DPI, often 1440 or 2880 ink dots, with image PPI.
  • Forgetting that cropping to a new aspect ratio removes pixels and shrinks the print.

Frequently asked questions

What is the difference between PPI and DPI?

PPI counts image pixels per inch of print. DPI counts the ink dots a printer places per inch, and an inkjet uses several dots to render each pixel. Print labs often say DPI when they mean PPI; for sizing a file, read their figure as pixels per inch.

How many megapixels do I need for an 8 × 10 print?

At 300 PPI, 8 × 10 inches needs 2400 × 3000 pixels, which is 7.2 megapixels. At 200 PPI the same print needs 1600 × 2000 pixels, or 3.2 megapixels, which most viewers will not tell apart at arm's length.

Why does a poster not need 300 PPI?

Viewing distance sets the detail the eye can resolve. A poster seen from two metres away looks clean at 100–150 PPI, because individual pixels are far smaller than the eye can separate at that distance.

Does changing the DPI value in Photoshop change the image?

Not if resampling is off. Changing the resolution field then only changes the stated print size; the pixel count stays the same. With resampling on, the software adds or removes pixels, which can soften the picture.

Why is my aspect ratio shown as an odd fraction?

The ratio is reduced exactly, so dimensions that are not clean multiples, such as 4032 × 3024, reduce to 4:3, while 5000 × 3333 stays as written because the two numbers share no common factor.

Is 72 PPI meaningful for web images?

No. Browsers draw images by pixel count and ignore the stored resolution tag, so a 1200-pixel-wide image appears the same whether its file says 72 or 300.

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). Image Resolution Calculator. Tools Directory. Retrieved October 27, 2026, from https://tools.milunir.com/photography/image-size-and-print/image-resolution-calculator/

MLA

Tools Directory Editorial Team. “Image Resolution Calculator.” Tools Directory, 20 Oct. 2026, https://tools.milunir.com/photography/image-size-and-print/image-resolution-calculator/. Accessed 27 Oct. 2026.

Chicago

Tools Directory Editorial Team. “Image Resolution Calculator.” Tools Directory. Last modified October 20, 2026. Accessed October 27, 2026. https://tools.milunir.com/photography/image-size-and-print/image-resolution-calculator/.

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