Conversion Form

PX
CH

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: pxch

Use px for fixed sizes, and ch for widths relative to the font.

Quick Reference: Unit Conversion by Tens

PXCH
10px1.25ch
20px2.5ch
30px3.75ch
40px5ch
50px6.25ch
60px7.5ch
70px8.75ch
80px10ch
90px11.25ch
100px12.5ch
110px13.75ch
120px15ch
130px16.25ch
140px17.5ch
150px18.75ch
160px20ch
170px21.25ch
180px22.5ch
190px23.75ch
200px25ch
210px26.25ch
220px27.5ch
230px28.75ch
240px30ch
250px31.25ch

Live Unit Preview

See how different CSS units affect the size of the box below:

10px

10rem

10em

10%

10vw

10vh

Common Mistake

Use px for fixed sizes, and ch for widths relative to the font.

Real Code Example

/* Mobile-first card with px → ch */
.card {
  padding: 0px;     /* undefinedch */
  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

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