Conversion Form

PX
REM

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: pxrem

Use rem for scalable typography. 16px = 1rem (base 16px). Perfect for accessibility.

Quick Reference: Unit Conversion by Tens

PXREM
10px0.625rem
20px1.25rem
30px1.875rem
40px2.5rem
50px3.125rem
60px3.75rem
70px4.375rem
80px5rem
90px5.625rem
100px6.25rem
110px6.875rem
120px7.5rem
130px8.125rem
140px8.75rem
150px9.375rem
160px10rem
170px10.625rem
180px11.25rem
190px11.875rem
200px12.5rem
210px13.125rem
220px13.75rem
230px14.375rem
240px15rem
250px15.625rem

Live Unit Preview

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

10px

10rem

10em

10%

10vw

10vh

Common Mistake

Avoid using px for font-size in responsive designs — it breaks accessibility.

Real Code Example

/* Mobile-first card with px → rem */
.card {
  padding: 0px;     /* undefinedrem */
  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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