Conversion Table
Root Em | Millimeters |
---|---|
0.01rem | 0.042mm |
0.03rem | 0.127mm |
0.05rem | 0.21mm |
0.08rem | 0.338mm |
0.1rem | 0.42mm |
0.15rem | 0.635mm |
0.2rem | 0.845mm |
0.5rem | 2.117mm |
0.625rem | 2.646mm |
0.75rem | 3.175mm |
0.875rem | 3.704mm |
1rem | 4.233mm |
1.125rem | 4.762mm |
1.25rem | 5.292mm |
1.375rem | 5.821mm |
1.5rem | 6.35mm |
1.625rem | 6.879mm |
1.75rem | 7.408mm |
1.875rem | 7.937mm |
2rem | 8.467mm |
2.125rem | 8.996mm |
2.25rem | 9.525mm |
2.375rem | 10.054mm |
2.5rem | 10.583mm |
2.625rem | 11.112mm |
2.75rem | 11.641mm |
2.875rem | 12.17mm |
3rem | 12.7mm |
3.125rem | 13.229mm |
3.25rem | 13.758mm |
3.375rem | 14.287mm |
3.5rem | 14.816mm |
3.625rem | 15.345mm |
3.75rem | 15.874mm |
3.875rem | 16.404mm |
4rem | 16.933mm |
5rem | 21.17mm |
6rem | 25.4mm |
8rem | 33.88mm |
10rem | 42.33mm |
15rem | 63.5mm |
20rem | 84.67mm |
30rem | 127mm |
40rem | 169.3mm |
50rem | 211.7mm |
60rem | 254mm |
80rem | 338.8mm |
100rem | 423.3mm |
Differences Between rem and mm
Root Em (rem) is a relative unit that scales according to the root element's font size, typically the HTML element. Millimeters (mm) are a metric unit of measurement commonly used in print media and physical dimensions. One millimeter is equal to 1/10 of a centimeter, making it useful for precise physical measurements.
Advantages of Using rem
Using rem units allows for better scalability and consistency across different screen sizes and resolutions. Since rem is relative to the root element's font size, adjusting the font size of the root element will proportionally scale all elements using rem units. This is particularly useful for responsive design and accessibility, as it respects user preferences for font size.
How to Convert rem to mm
To convert rem to millimeters, you need to know the root element's font size. By default, most browsers set the root font size to 16px. The formula for conversion is:
mm = rem * root font size * 0.2646
For example, to convert 2rem to millimeters, assuming the root font size is 16px:
2rem * 16px * 0.2646 = 8.467mm
Frequently Asked Questions
Why should I use rem instead of mm?
Using rem allows for more scalable and consistent layouts across different screen sizes and user settings, improving accessibility.
How do I set the root font size?
You can set the root font size using CSS on the HTML element. For example:
html {
font-size: 16px;
}
Can I use rem for all elements?
Yes, you can use rem for most elements to ensure consistency. However, for precise physical measurements, mm might be more suitable.