PX → EM Converter
Converting from PX to EM is common when switching from great for pixel-perfect layouts but not flexible for responsive design. to ideal when you need sizing relative to parent elements. in CSS projects.
Conversion Form
About the Unit
Pixel (px): A pixel is the smallest visible measurement unit on a digital screen, commonly used to describe the resolution and dimensions of graphical elements and text. In a CSS context, the pixel is an absolute unit, but its perception can vary depending on the device's pixel density (such as on Retina displays). Although it is a fixed unit, the pixel value in CSS is standardized to ensure consistency across devices with different resolutions. For example, an element with 100px width will always render with 100 pixels of width on the screen, but on devices with higher pixel density, the content display may appear sharper. The px unit is widely used in graphical interface design, typography, and other visual properties, being the predominant choice in many web design approaches.
Pro Tip: px → em
Px to em: use for nested component sizing based on parent text size.
Quick Reference: Unit Conversion by Tens
| PX | EM |
|---|---|
| 10px | 0.625em |
| 20px | 1.25em |
| 30px | 1.875em |
| 40px | 2.5em |
| 50px | 3.125em |
| 60px | 3.75em |
| 70px | 4.375em |
| 80px | 5em |
| 90px | 5.625em |
| 100px | 6.25em |
| 110px | 6.875em |
| 120px | 7.5em |
| 130px | 8.125em |
| 140px | 8.75em |
| 150px | 9.375em |
| 160px | 10em |
| 170px | 10.625em |
| 180px | 11.25em |
| 190px | 11.875em |
| 200px | 12.5em |
| 210px | 13.125em |
| 220px | 13.75em |
| 230px | 14.375em |
| 240px | 15em |
| 250px | 15.625em |
Live Unit Preview
See how different CSS units affect the size of the box below:
10px
10rem
10em
10%
10vw
10vh
Common Mistake
Px to em: use for nested component sizing based on parent text size.
Real Code Example
/* Mobile-first card with px → em */
.card {
padding: 0px; /* undefinedem */
font-size: 1.5rem;
width: min(90vw, 40ch);
}Frequently Asked Questions About PX
When should I use px instead of px?
Use px for pixel-perfect control in fixed layouts.
How many px is 1px?
1px = 0.0625rem assuming a 16px base.
Is px affected by zoom?
Yes, it scales with browser zoom but remains fixed in layout.
Is px good for fonts?
Not recommended for fonts due to poor accessibility scaling.
Keyboard Shortcuts
- Ctrl + C: Convert
- Ctrl + I: Invert units
- Esc: Reset values