PX to MM Converter
Conversion Guide
1. Determine the screen PPI (pixels per inch). 2. Convert px to inches: px / PPI. 3. Convert inches to mm: multiply by 25.4. Example: At 96 PPI, 96px / 96 * 25.4 = 25.4mm.
Pixels to MM Conversion Table (Screen density: 96 PPI)
| PX | MM | Actions |
|---|---|---|
| 1 | 0.2646 | |
| 50 | 13.2292 | |
| 100 | 26.4583 | |
| 200 | 52.9167 | |
| 500 | 132.2917 | |
| 1000 | 264.5833 |
Frequently Asked Questions
Basics
What is PX?
A CSS pixel (px) is a standardized unit of measurement that aims to make elements appear at similar physical sizes across different devices. Unlike physical screen pixels, CSS pixels are an abstraction that automatically scales based on device characteristics and user zoom settings.
Are CSS pixels the same as physical screen pixels?
No. On high-DPI (Retina) displays, one CSS pixel may actually use multiple physical screen pixels. For example, on a 2x display, 1 CSS pixel equals 4 physical pixels (2x2).
When should I use pixels vs relative units?
Use pixels for precise visual elements that should maintain their exact appearance, like borders (1px), box shadows, and small decorative details. For layout and typography, prefer relative units (rem, em, %) to ensure better accessibility and responsive design.
Do pixel-based layouts work well on mobile?
Fixed pixel layouts often break on mobile devices due to varying screen sizes. It's better to use relative units for layouts to ensure your design adapts smoothly across devices.
What happens to pixel values when users zoom?
CSS pixels scale proportionally when users zoom. If a user zooms to 200%, a 16px font becomes equivalent to 32px, ensuring content remains readable.
Do pixels affect accessibility?
Yes. Using fixed pixel values for text and layout can prevent proper scaling when users change their browser's font size settings. This creates accessibility issues for users who need larger text.
What is MM?
Millimeters (mm) are absolute-length units that correspond to physical millimeters, primarily used in print design.
How accurate are mm units on screens?
The accuracy of mm units on screens depends on the device's DPI settings and physical characteristics. They're more reliable in print.
When should I use mm?
Use mm in print stylesheets or when designing for international markets that use the metric system.
Conversion
How to convert PX to MM?
To convert PX to MM, use the following formula:
px / 3.78