SizeKit

SizeKit reference

Print Size Calculator

Convert image pixels and DPI into printable inches, centimeters, and millimeters.

Print size is pixels divided by DPI. For example, 2480 x 3508 px at 300 DPI prints at about 8.27 x 11.69 inches.

SizeKit

Common results first

These cover frequent one-off checks. Use the full calculator below only for custom values.

ISO A A4 210 x 297 mm 2480 x 3508 px at 300 DPI Open North America US Letter 215.9 x 279.4 mm 2550 x 3300 px at 300 DPI Open Print 2480 x 3508 px 8.27 x 11.69 in at 300 DPI Customize Ratio 1920 x 1080 16:9 common video / screen ratio Customize

SizeKit

Three calculation modes

Pick the mode that matches what you already know.

1 Pixels to Print Size You have an image (width x height in pixels) and a target DPI. Find the maximum print size in inches, cm, and mm. 2 Print Size to Pixels You have a target print size (e.g. 4x6 in or A4) and a DPI. Find the required pixel dimensions. 3 Max Print Size at quality You have an image and want to know how large it can print at 300 / 150 / 96 DPI without losing quality.

Mode 1

Pixels to Print Size

Enter image pixels and target DPI. Result includes inches, centimeters, millimeters, and a quality flag.

Formula: inches = pixels / DPI. centimeters = inches x 2.54. millimeters = inches x 25.4. Quality: 300+ DPI for photo print, 150 DPI for office print, 96 DPI for on-screen only.

Mode 2

Print Size to Pixels

Common print sizes converted to required pixels at 300 DPI (photo) and 150 DPI (office).

Print sizeInchesPixels at 300 DPIPixels at 150 DPI
A48.27 x 11.69 in2480 x 3508 px1240 x 1754 px
US Letter8.5 x 11 in2550 x 3300 px1275 x 1650 px
A311.69 x 16.54 in3508 x 4961 px1754 x 2480 px
A55.83 x 8.27 in1748 x 2480 px874 x 1240 px
4x6 photo4 x 6 in1200 x 1800 px600 x 900 px
5x7 photo5 x 7 in1500 x 2100 px750 x 1050 px
8x10 photo8 x 10 in2400 x 3000 px1200 x 1500 px
11x14 print11 x 14 in3300 x 4200 px1650 x 2100 px
16x20 poster16 x 20 in4800 x 6000 px2400 x 3000 px

Formula: pixels = round(inches x DPI). For custom sizes, use Mode 1 above with your target inches converted to pixels.

Mode 3

Max Print Size at quality target

For common image resolutions, here is the largest print size at each quality level.

Image pixelsMax at 300 DPI (photo)Max at 150 DPI (office)Max at 96 DPI (screen)
1920 x 10806.4 x 3.6 in12.8 x 7.2 in20 x 11.25 in
2480 x 35088.27 x 11.69 in (A4)16.53 x 23.39 in25.83 x 36.54 in
3000 x 200010 x 6.67 in20 x 13.33 in31.25 x 20.83 in
4000 x 300013.33 x 10 in26.67 x 20 in41.67 x 31.25 in
6000 x 400020 x 13.33 in40 x 26.67 in62.5 x 41.67 in
8192 x 546427.3 x 18.21 in54.6 x 36.43 in85.3 x 56.92 in

Formula: max inches = pixels / DPI. Going below 300 DPI for photo print reduces detail; below 150 DPI starts to show pixelation on close inspection.

SizeKit

Use this tool for

When this calculator is the right answer.

  • Sizing a digital image before sending it to print.
  • Checking whether a photo has enough resolution to print at a given size.
  • Converting between pixels, inches, centimeters, and millimeters for print or design files.
  • Confirming DPI requirements for photo lab, business card, poster, or catalog print.

SizeKit

Do not use this tool for

Cases where the answer is something else.

  • Mouse DPI / gaming sensitivity. Use the gaming mouse documentation. SizeKit DPI refers to image pixels per inch, not pointer sensitivity.
  • On-screen image sizing. Screen images use absolute pixels; DPI does not change how they look. Use the Aspect Ratio Calculator.
  • Calculating physical paper sizes. Paper sizes are defined in mm by ISO/ANSI standards. See all paper sizes or A4 size.
  • Upscaling image resolution. This tool computes the print size of existing pixels. It does not add detail to a small image.

SizeKit

Common mistakes

Errors that lead to wrong print results.

  • Setting DPI in the image without resampling. Changing DPI metadata does not change the pixel count. The print size changes, but the image data is unchanged.
  • Treating 72 DPI as a print value. 72 DPI is a screen convention. Photo print requires 300 DPI; office print 150 DPI is acceptable.
  • Ignoring aspect ratio when scaling. A 4x6 photo (2:3) cannot fill an 8x10 frame (4:5) without cropping. Use the Aspect Ratio Calculator.
  • Using DPI instead of PPI in screen contexts. DPI is for print; PPI is for screens. Most software treats them as synonyms but the underlying concept differs.

SizeKit

Source and calculation method

Formulas and conventions used by SizeKit.

Source type
Calculated, standard formula
Conversion uses the inch (25.4 mm exact) and standard DPI definition (dots per inch). Results are rounded to the nearest pixel.
Calculation method
Browser-side, no upload
All calculations run in the browser. Inputs are not sent to a server. Same formula across modes.
Last reviewed
2026-05-29
Conversion constants are stable. SizeKit re-verifies edge cases (rounding, foreign units) twice a year.

SizeKit

Related paths

Use a reference page if you know the size name; use a calculator only when your value is custom.

A4

A4 size page

Get mm, inches, and common pixel presets without configuring anything.
PAPER

All paper sizes

Browse by name, country, and use case.
SOC

Social and web sizes

Find recommended export dimensions.

SizeKit

FAQ

Practical calculator questions.

How do I calculate print size from pixels?

The print size of an image is calculated by dividing its pixel dimensions by DPI. For example, 2480 x 3508 pixels at 300 DPI prints at 8.27 x 11.69 inches (A4).

How many pixels do I need for an 8x10 print?

At 300 DPI photo quality, 8x10 inches requires 2400 x 3000 pixels. At 150 DPI office quality, 1200 x 1500 pixels.

What DPI should I use for printing?

300 DPI is the standard for photo print. 150 DPI is acceptable for office documents. Below 150 DPI shows pixelation on close inspection.

Is DPI the same as PPI?

DPI is for print (dots per inch); PPI is for screens (pixels per inch). Most software treats them as synonyms, but the underlying concept differs.