1.5 rem equals 24 pixels (px).
The conversion from rem to pixels depends on the root font size set in the browser, which is often 16px by default. So, multiplying 1.5 by 16 gives the pixel value.
Conversion Tool
Result in px:
Conversion Formula
The formula for converting rem to px is:
pixels = rem × root font size in pixels
This works because 1 rem unit is equal to the font size of the root element, which is commonly 16px. So multiplying the rem value by 16 gives the equivalent px value.
For example, converting 1.5 rem to px:
- Start with rem value: 1.5
- Multiply by root font size (16px): 1.5 × 16
- Result: 24px
Conversion Example
- Convert 2 rem to px:
- 2 × 16 = 32px
- Multiply rem value, 2, by 16 (root font size)
- Result is 32 pixels
- Convert 0.75 rem to px:
- 0.75 × 16 = 12px
- Multiply rem 0.75 by 16
- Gives 12 pixels
- Convert 3.2 rem to px:
- 3.2 × 16 = 51.2px
- Multiply rem 3.2 by 16
- Result: 51.2 pixels
- Convert 0 rem to px:
- 0 × 16 = 0px
- No size, so zero pixels
- Convert -1.5 rem to px:
- -1.5 × 16 = -24px
- Negative rem values multiply just same
- Resulting in negative pixel value
Conversion Chart
The table below shows rem values from -23.5 to 26.5 and their equivalent pixel values assuming the root font size is 16px. To use the chart, find your rem value in the left column and read the corresponding px value on the right.
| Rem | Pixels (px) |
|---|---|
| -23.5 | -376 |
| -20 | -320 |
| -15 | -240 |
| -10 | -160 |
| -5 | -80 |
| -1 | -16 |
| 0 | 0 |
| 1 | 16 |
| 1.5 | 24 |
| 2 | 32 |
| 3 | 48 |
| 5 | 80 |
| 10 | 160 |
| 15 | 240 |
| 20 | 320 |
| 25 | 400 |
| 26.5 | 424 |
Related Conversion Questions
- How many pixels does 1.5 rem equal if the browser root font size is changed?
- What is the px value for 1.5 rem with a default 16px root font size?
- Does 1.5 rem always convert to 24 pixels in all browsers?
- How to convert 1.5 rem to px when root font size is 20px?
- Why does 1.5 rem equal 24 px in CSS?
- Can 1.5 rem be less than 24 pixels under some settings?
- What formula to use for converting 1.5 rem to pixels?
Conversion Definitions
rem: Rem stands for “root em” and it’s a CSS unit based on the font size of the root element, usually the <html> tag. Using rem allows scalable and relative sizing that adjusts if root font size changes, helpful for responsive designs and accessibility.
px: Pixels (px) are absolute units representing single dots on a screen. They provide precise control over element sizes, unaffected by user settings or scaling. Pixels are fixed units, useful for exact layout and image dimensions in web design and graphics.
Conversion FAQs
What happens if the root font size is changed from 16px?
If the root font size changes, the pixel value for rem units changes proportionally. For example, if root size is 20px, 1.5 rem equals 30px because 1.5 × 20 = 30. Rem depends on the root font size, so px values adjust automatically.
Can rem values be negative in CSS and how does it affect px conversion?
Yes, negative rem values are valid in CSS, often for positioning or offsetting elements. The pixel conversion multiplies the negative rem by root font size, resulting in a negative pixel value, which moves elements in the opposite direction.
Why use rem instead of px in CSS?
Rem units provide scalability and adaptability. They allow font sizes and spacing to adjust if root font size changes, improving accessibility and responsiveness. Pixels are fixed and do not scale with user preferences or device settings, making rem better for flexible layouts.
Is the root font size always 16px?
No, the root font size can be modified by browser defaults, user styles, or CSS rules. While 16px is common default, some browsers or websites might set different sizes, affecting rem to px conversion. Always check or set root font size explicitly when precision needed.
How precise is the rem to px conversion?
Conversion is mathematically precise since it’s multiplication by root font size. However, rendering on screen might slightly differ due to device pixel ratio, zoom levels, or browser rendering quirks. The formula provides exact values but actual display can vary slightly.
Last Updated : 23 June, 2025
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