FREE TOOL: Get Picture-Perfect Prints – Try Our Free Print Size Calculator

Printing our photos is on the rise. Do your prints look soft or blocky when they come back from the lab? Let our Print Size Calculator help.

Just enter the dimensions of the physical size you require, along with the PPI your lab requires, and it will tell you the pixel dimensions your file should have for a sharp result.

How to use the calculator:

1. Enter the Width and Height of the print.
2. Choose Units (in/cm/mm).
3. Set PPI. 300 is a good all-round choice; 240–360 is common, but your print lab will tell you what they need.
4. Read the required pixels.
5. Resize (and crop if necessary) your image in Photoshop, Affinity or another editor to conform to those pixel dimensions.
6. Upload to your lab and order your prints.

PPI vs DPI (quick explainer)

• PPI (pixels per inch) describes your image. It’s how many pixels you want per inch of print.
• DPI (dots per inch) describes the printer’s dot grid. It’s a hardware/ink setting, not your file’s resolution.
• Many websites/labs say “DPI” when they mean PPI. In practice, when you see “300 DPI” on a photo upload page, assume they mean 300 PPI for the image. This calculator uses PPI to compute required pixel dimensions.

Now, you should never see blocky-looking prints again. You’ll know exactly how big your digital image needs to be in order to print a certain size.

If you found this tool helpful, let us know in the comments. If you found something broken, missing or confusing with this tool, or have any suggestions for future iterations, also leave us a comment, and we’ll take a look.

This is the first in a new series of web tools we’re releasing for photographers and filmmakers. So, let us know what problems you’re facing that we might be able to help solve with a new tool!

For website owners: embed this on your site

Quick start

Paste this where you want the calculator to appear (WordPress “Custom HTML” block is fine):

<div class="diyp-print-calculator"></div>
<link rel="stylesheet" href="https://www.diyphotography.net/diyptools/diyp-print-calc.min.css">
<script src="https://www,diyphotography.net/diyptools/diyp-print-calc.min.js" async defer></script>

You can add multiple calculators on a page – just add more <div class="diyp-print-calculator"> blocks. All logic runs client-side.

Optional parameters (data-attributes)

Add these to the <div class="diyp-print-calculator"> to set defaults or theme.

Attribute	Values	Default	What it does
data-title	Any text	DIYPhotography.net Print Size Calculator	Sets the visible header title.
data-ppi	Integer (e.g. 240)	300	Sets the starting PPI.
data-units	in | cm | mm	in	Sets the starting units for width/height.
data-theme	light | dark	light	Chooses the color theme.

Examples

Dark theme, centimetres, PPI 240:

<div class="diyp-print-calculator" data-theme="dark" data-units="cm" data-ppi="240"></div>

Custom title:

<div class="diyp-print-calculator" data-title="Acme Lab — Print Size Helper"></div>

Notes for embedders

• Pixel math: pixels = inches × PPI (the tool converts cm/mm to inches for the calculation).
• Rounding: pixel values are rounded to whole numbers; megapixels are shown to 2 decimals.
• Styling: CSS is namespaced under .diyp-print-calculator to reduce conflicts.
• Multiple instances: the script auto-initialises any .diyp-print-calculator it finds, including ones added later via AJAX.
• Performance: no network calls after the CSS/JS files load; everything runs in the browser.

Last updated: December 6th, 2025

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