CM to PX Converter Online
with Conversion Table

In design and development workflows, it’s common to switch between physical units and digital units.

A client might hand you a print specification like “120 cm wide banner” or “5 cm high logo strip”, and you need to translate that into pixels (px) for the web, UI mockup, or digital asset.

Without a reliable method, this translation becomes guesswork — and brand consistency suffers.

As the founder of an small web-design agency, I’ve seen this scenario many times: print-sized templates delivered in centimetres, then someone on the digital side scrambles to approximate pixel sizes, leading to mismatched layouts, visual inconsistencies, or extra rounds of revisions.

That’s why we built this CM to PX Converter — so our team (and now you) can instantly convert centimetres (cm) into the exact pixel (px) equivalent for web or print-prepped digital assets.

👉 Try the converter widget at the top of this page and then read on to understand why it matters, how it works, and how you should use it.

What are Centimetres (cm) and Pixels (px)?

Centimetre (cm)

A centimetre is a physical unit of length in the metric system — 1 cm = 0.01 m. It’s used widely in print design, signage, packaging and product dimensions. When you measure a paper-print size, packaging dimension or physical mock-up, chances are the values are expressed in centimetres (or millimetres).

Pixel (px)

A pixel is a digital unit: “picture element” — the smallest controllable dot on a digital display. But its physical size can vary depending on screen resolution, device pixel density (PPI or DPI), zoom level, or CSS scaling. Because pixels are relative, conversion from physical units like centimetres requires context (resolution).

In short: centimetres are absolute physical units, pixels are relative digital units. When converting from cm → px, you’re mapping the physical world into digital space — and you need the right “translator”.

Why Convert Centimetres to Pixels?

Here are the real-world situations we encounter at our agency where CM→PX conversions are critical:

• Print → Web Branded Assets: A brand guideline might specify “logo width: 7 cm” for packaging. For the website hero section you must convert that into pixels so it looks visually proportional.

• Signage and Digital Displays: A shop signage mock-up provided in cm needs pixel dimensions for a screen preview or interactive mock-up.

• Responsive Web & UI Design: You may start with a physical specification (10 cm height) for an element in a kiosk UI or touch interface; converting it to px ensures your digital design reflects real-world scale.

• Print-Prepared Graphics in Digital Files: Even for print-ready files, designers often work in pixels before switching to print units. Converting cm to px (or vice versa) helps maintain precision.

By using a dedicated CM to PX converter, you remove ambiguity, avoid calculation errors, and save time—letting your team focus on design rather than unit mismatch.

The Key Variable: Understanding PPI / DPI

You cannot convert cm into px accurately without knowing the resolution, generally expressed as PPI (Pixels Per Inch) or DPI (Dots Per Inch for print). Here’s what you need to know:

• PPI (Pixels Per Inch) indicates how many pixels fit into one inch of physical space on a screen or image.

• DPI (Dots Per Inch) often refers to printed output (dots of ink) but for conversion purposes it’s often used interchangeably with PPI.

• Common values:

  • 96 PPI: Standard default for web/CSS.

  • 72 PPI: Older legacy standard (less common now).

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

• Without specifying PPI/DPI, you’d have no fixed conversion factor — 1 cm in px on a low-density screen might differ from a high-density screen.

Whenever you use our CM→PX tool (or any conversion), ensure you select or input the correct PPI value for your medium.

CM to PX Conversion Formula + Example

Here’s the formula we use (and you’ll see it under the hood of our tool):

Why ÷ 2.54? Because 1 inch = 2.54 cm. So converting cm → inches → pixels involves dividing by 2.54.

Example 1: Web Design (96 PPI)

Let’s say you want to design an element that is 12 cm wide for the web (standard 96 PPI).
Calculation:

So you’d set your width to ~454px for accurate visual proportion.

Example 2: Print-Ready File (300 PPI)

If you take the same 12 cm but want it rendered as a high-quality image for print, at 300 PPI:

That’s a massive difference: the same 12 cm size becomes ~1,417px wide.

This is why specifying the target resolution (PPI/DPI) is vital.

How to Use the CM to PX Converter Tool

We designed our converter to be fast, accurate and developer/designer-friendly.

1. Enter the value in centimetres (cm) – e.g., 12.

2. Select or enter the PPI (Pixels Per Inch) – presets like 96, 150, 300, or a custom value.

3. The pixel (px) result updates instantly — no manual math required.

4. Click “Copy” (if available) to paste into CSS, Figma/Sketch, Photoshop or code.

5. Use this value when setting width/height in px, creating artboards, exporting assets or specifying dimensions to clients.

This instant conversion tool replaces manual spreadsheets or calculator tabs and ensures a consistent standard across your team.

Advantages + Use Cases (Founder’s Perspective)

From running an agency I can say: unit conversion is a tiny step that’s easily overlooked, but consistency is what differentiates professional design.

• Speed: Seconds instead of minutes calculating or guessing conversions.

• Accuracy: Eliminates rounding errors or formula mis-entry (e.g., forgetting to divide by 2.54).

• Consistency: Every team member uses the same conversion logic — reducing discrepancies between designers and developers.

• Client-Friendly: When clients ask “why does my 10 cm logo look small on the site?”, you can show the conversion and explain pixel density clearly.

• Workflow Efficiency: Helps when building landing pages, responsive assets, digital signage or print assets derived from digital files — ensures your starting pixel value matches real-world dimensions.

Think of it as a small tool with big impact: when scaling across dozens of pages or client assets, these conversions accumulate time-savings and reduce costly mistakes.

Best Practices for Converting CM to PX

Here are pro tips to ensure you’re getting each conversion right:

1. Always Confirm the Target Medium

Ask: is this for web, mobile, print, digital signage, or UI mock-up? Choose the appropriate PPI (96, 150, 300, or custom).

2. Avoid Relying on cm Units in CSS

While CSS allows width: 10cm;, it’s unreliable because browsers assume a PPI (often 96) and screens vary. Instead, convert to px for consistent visual results across devices.

3. Round Sensibly

If your formula gives 453.54px, it's okay to round to 454px. Minor differences rarely matter visually — but consistency does.

4. Communicate Resolution (PPI) with Clients

If delivering design files that will be printed, ask the print shop for their DPI requirement — then convert accordingly. Don’t assume 300 PPI in every case.

5. Use Related Conversions for Responsive Design

Once you have your px value from cm, you may want to further convert px → rem, px → vw, or px → em for responsive layouts. Check our other tools below.