design & development tools - Pixel to MM

PX to MM Converter Online
with Conversion Table

Your Go-to Tool for Converting Pixels to Millimeters (MM to PX) – Free and Easy!

PX ↔ MM Converter

Convert pixels to millimeters and millimeters to pixels with custom PPI. Ideal for web, UI, and print design.

Pixels to Millimeters

Example: 16, 24, 96, 300
Millimeters
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Formula: (px ÷ PPI) × 25.4

Millimeters to Pixels

Example: 10, 25.4, 100
Pixels
—
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Formula: (mm ÷ 25.4) × PPI

Enter your screen/device PPI to get accurate conversions.
Quick presets:

Quick px → mm reference (96 PPI)

Pixels (px) Millimeters (mm)
16 px4.23 mm
24 px6.35 mm
96 px25.40 mm (1 inch)
150 px39.69 mm
300 px79.38 mm

Note: pixel-to-millimeter values always depend on the PPI (pixels per inch). For most web layouts, 96 PPI is used as the reference.

Common PX to MM sizes at 96 PPI…

  • 1 px in mm is 0.26 mm

  • 2 pixels to mm is 0.53 mm

  • 4 px to millimeters is 1.06 mm

  • 5 pixels in mm is 1.32 mm

  • 8 px to mm is 2.12 mm

  • 10 pixels to mm is 2.65 mm

  • 12 px into millimeters is 3.17 mm

  • 15 pixels to mm is 3.97 mm

Common PX MM sizes at 96 PPI…

  • 20 px to mm is 5.29 mm

  • 25 pixels to millimeters is 6.61 mm

  • 30 px in mm is 7.94 mm

  • 35 pixels to mm is 9.26 mm

  • 40 px to millimeters is 10.58 mm

  • 50 pixels in mm is 13.23 mm

  • 60 px in mm is 15.87 mm

  • 70 pixels to mm is 18.52 mm

Common PX to MM sizes at 96 PPI…

  • 80 px to mm is 21.17 mm

  • 90 pixels to mm is 23.82 mm

  • 96 px to mm is 25.39 mm

  • 100 pixels to mm is 26.46 mm

  • 120 px in mm is 31.75 mm

  • 140 pixels to mm is 37.04 mm

  • 150 px to millimeters is 39.69 mm

  • 160 pixels to mm is 42.33 mm

Common Pixel to MM sizes at 96 PPI…

  • 180 px to mm is 47.62 mm

  • 200 pixels to mm is 52.92 mm

  • 220 px to mm is 58.21 mm

  • 250 pixels in mm is 66.15 mm

  • 300 px to mm is 79.37 mm

  • 350 pixels to mm is 92.61 mm

  • 400 px to mm is 105.83 mm

  • 500 pixels to mm is 132.29 mm

The Ultimate Guide to Converting Pixel to MM Converter...

Ever questioned: How big is this design in real life?

When you’re designing on a screen but the final output ends up on packaging, signage, or a printed layout, that question becomes critical.

In the digital world, we measure in pixels (px). In the physical world, we deal with millimeters (mm). Bridging that gap accurately is where the PX to MM Converter comes in.

As the founder of 60pixel - a design and web development agency, I built this converter because at times, my team needs to translate digital measurements into real-world dimensions — quickly, reliably, and without manual math.

Whether we were designing a website mockup for a print display or sizing brand assets for packaging, this tool became essential to our workflow.

Let’s break down what this conversion really means, how it works, and why it’s so important for anyone working across both print and digital mediums.

What Are Pixels and Millimeters?

Pixel (px)

A pixel (short for “picture element”) is the smallest visible unit of a digital image or display. It has no fixed physical size — its appearance depends on the resolution or PPI (pixels per inch) of the screen or digital file.

On a high-resolution smartphone display, a pixel might be tiny; on an older desktop monitor, it might be noticeably larger. This variability is what makes conversions between pixels and real-world measurements more complex.

Millimeter (mm)

A millimeter is a physical unit of length in the metric system. It’s fixed — 10mm make 1cm, and 25.4mm make 1 inch. It’s used universally in print design, product packaging, and engineering specifications.

So, while millimeters are absolute, pixels are relative. To convert between them accurately, we need one more piece of information — the screen or file’s PPI (Pixels Per Inch).

Why Convert Pixels to Millimeters?

Converting pixels to millimeters isn’t just a math exercise — it’s a practical necessity across many creative and technical fields. Here are some common scenarios we see at our agency:

1. Print Design & Mockups

If you’re designing a print-ready banner or label in Photoshop, your design might be in pixels. But printers need measurements in millimeters (or centimeters). Converting ensures your layout prints at the exact intended size.

2. UI/UX Design

When designing mobile or embedded interfaces, physical size matters — especially for touch targets and real-world devices. Converting pixels to mm helps designers understand how large an element feels on different screens.

3. Packaging & Product Design

Brands often provide packaging templates in millimeters. If your design assets are digital (in pixels), you’ll need to translate those dimensions to match the print-ready specs perfectly.

4. Hardware & Screen Visualization

When testing or presenting mockups on screens, knowing how many millimeters a pixel represents helps maintain proportion consistency across multiple devices.

In short, pixels define the digital world, but millimeters define the real one — and every serious designer or developer needs to move seamlessly between the two.

The Key Variable: Understanding PPI (Pixels Per Inch)

You cannot convert px to mm accurately without knowing PPI (or DPI for print).

Here’s how it works:

  • PPI (Pixels Per Inch) determines how many pixels fit into a physical inch of space.

  • Higher PPI = smaller pixels = more detail per inch.

  • Lower PPI = larger pixels = fewer pixels per inch.

Common standards:

  • 96 PPI: Default for web and screen design.

  • 72 PPI: Legacy standard from early Apple displays.

  • 300 PPI: Print standard for high-quality materials.

So, if your file is designed for web (96 PPI), 1 pixel will represent more millimeters than if it’s designed for print (300 PPI).

Conversion Formula: PX to MM

The formula to convert pixels to millimeters is:

Millimeters = (Pixels × 25.4) ÷ PPI

Where:

  • 25.4 = millimeters per inch

  • PPI = pixels per inch of your display or file

Example 1: For Web Design (96 PPI)

Let’s convert 500px to millimeters:

MM = (500 × 25.4) ÷ 96
MM = 12700 ÷ 96
MM = 132.29 mm

So, 500px ≈ 132.3 mm at 96 PPI.

Example 2: For Print Design (300 PPI)

MM = (500 × 25.4) ÷ 300
MM = 12700 ÷ 300
MM = 42.33 mm

At 300 PPI, 500px is just 42.3 mm — less than half the size.
This difference highlights why PPI must always be specified for accurate conversions.

How to Use the Pixel to MM Converter Tool

Our Pixel to Millimeter Converter makes this conversion effortless.
Here’s how it works:

  1. Enter Your Pixel Value
    Input any number of pixels (e.g., 1920).

  2. Select or Enter Your PPI (Pixels Per Inch)

    • Choose from preset values: 72, 96, 150, 300.

    • Or enter a custom value for your specific device or file.

  3. View Instant Results
    The millimeter equivalent appears instantly—no calculation required.

  4. Copy the Result
    Click the copy icon to paste it into your design notes, CSS, or client documentation.

This tool updates results in real time, so you can experiment with different PPIs and immediately see how scale changes between web and print.

Advantages and Founder’s Perspective

Running a creative agency means juggling design precision and efficiency every day.
This converter is part of the internal toolkit we use to keep those two in perfect balance.

Here’s what makes it indispensable:

  • Accuracy Without Effort: No manual math or guesswork—just precise conversions every time.

  • Consistency Across Projects: Every team member uses the same conversion logic, ensuring pixel-perfect brand consistency.

  • Time Efficiency: Converts in seconds; ideal during design presentations or client calls.

  • Client Transparency: Clients often wonder why a 2000px image looks “too small” in print. Showing them the conversion helps explain pixel density clearly.

  • Cross-Medium Clarity: Keeps digital and print teams aligned on dimensions, preventing costly reprints or layout errors.

As a founder, I can confidently say — tools like this save hours of back-and-forth communication and keep projects running smoothly.

Best Practices for Converting PX to MM

  1. Always Confirm the PPI:
    Before converting, know your target medium. Use 96 PPI for web and 300 PPI for print.

  2. Avoid Using Pixels in Print Specs:
    Printers don’t understand pixels; always provide millimeter or centimeter values.

  3. Round Carefully:
    If you get a result like 42.33mm, round sensibly based on the material or margin tolerance.

  4. Test on Multiple Devices:
    A 200px element may “feel” different across devices; always check scaling in real-world previews.

  5. Use Related Tools:
    Pair this with our MM to PX Converter when designing back-and-forth between digital and print.

FAQs

Here are some of the frequently asked questions about conversions…

That depends on PPI. At 96 PPI, 1 pixel = 0.2646 mm. At 300 PPI, 1 pixel = 0.0847 mm.

Most web projects use 96 PPI, but always test on multiple devices.

Absolutely. It’s perfect for ensuring your digital assets match physical packaging templates provided in mm.

Because each screen has a different pixel density (PPI). A 500px element looks smaller on high-resolution devices.

PPI measures screen resolution; DPI measures print resolution. They’re often used interchangeably but refer to different mediums.

Use our MM to PX Converter, which applies the reverse formula:
Pixels = (Millimeters × PPI) ÷ 25.4

Related tools you might find helpful

If you work with CSS, responsive layouts, or UI design, these converters will help you switch between different units quickly.

Each tool solves a specific use case – whether you're adjusting font sizes, spacing, or converting print measurements to screen pixels. Explore the full set below to speed up your workflow…

Complete list of conversion tools

  • PX to CM Converter – Convert pixels into centimeters for print-friendly layouts and accurate sizing.

  • CM to PX Converter – Convert centimeters to pixels when designing for screens or digital assets.

  • PX to REM Converter – Convert pixels to rem for scalable and accessible typography.

  • REM to PX Converter – Convert rem values back to fixed pixel units for precise layout control.

  • PX to Inches Converter – Convert pixels into inches for print sizes or physical measurements.

  • Inches to PX Converter – Convert inches into pixel dimensions based on standard screen density.

  • MM to PX Converter – Convert millimeters to pixels for UI, print, and product mockups.

  • PX to MM Converter – Convert pixels to millimeters with accurate unit mapping.

  • MM to Inches Converter – Convert millimeters into inch values for sizing and print design.

  • Inches to MM Converter – Convert inches into millimeters for exact physical measurements.

  • VW to PX Converter – Convert viewport-width units into pixel values for responsive layouts.

  • PX to VW Converter – Convert pixel values into viewport-width units for fluid UI scaling.

Conclusion

The PX to MM Converter is more than just a calculator — it’s a design bridge between pixels and paper. Whether you’re preparing web assets for print or aligning digital and physical dimensions, this tool ensures every pixel translates perfectly into the real world.

As an agency founder, I believe precision is what separates good design from great design. With this converter, our team — and now yours — can achieve that precision effortlessly.

Bookmark this page, share it with your team, and explore our other design tools to make your workflow faster, smarter, and error-free.

Cheers,
Kuldeep