Type into any of the text boxes






CSS Font Size Converter: px to percentage to em

Start typing in any of the boxes to convert the units

CSS Font Sizing: Px vs Em vs Rem

It has been discussed many times that concerns about pixels vs em vs rem and that font property to use and once. Though are many articles online, this subject is terribly confusing given however the usage of those font properties differs supported the requirements of our comes. 

As an example, some individuals counsel to not use mounted picture element values at the bottom level (HTML and body elements) because the user won't get the chance to reset the font size to their specifications. But, for individuals who are passionate about bootstrap, this is often not judicious. We have a tendency to find ourselves having a set base price in picture elements and got to produce our entire project’s font properties relative to the bottom pixel values.

This article explains the distinction between these font properties and the way best to use them. Of course, there is no right thanks to doing that and an outsized part of that font filler's to use and the way is, for the most part, settled supported our understanding of those font sizing units and also the project in question.

Pixels px

Before the appearance of responsive style, the picture element was widely used because of the font filler for everything from typography to dimension, padding, and height. However, pixels are fixed-size units and don't amendment support the dimensions of the viewport or climbable. 

If you wish to create a responsive website exploitation pixels, it will get terribly tough to stay track of all the picture element primarily based values throughout the CSS sheet, as well as the values at intervals media queries. So, What font property will permit us to create borderline changes to our CSS stylesheet but still be scalable? That’s wherever em and rem units get the image.

If you’re setting all of your font sizes, component sizes, and spacing in pixels, you’re not treating the top user with respect. In most browsers, a user will set their default browser font size to be a unique size to the default (typically 16px). If the user sets their default to 20px, all font sizes ought to scale consequently.

However, if the website expressly sets font sizes in pixels, a heading set at 30px can perpetually be 30px. that may sound nice from a designer/developer's purpose of reading - however, you’re not the user, stop creating websites for yourself.

Thankfully, setting font sizes in pixels doesn’t utterly ruin accessibility. The user will still center and out with ctrl and +/-. However, we are able to do higher.

Element em

Em may be a versatile, climbable unit that's regenerated by the browser into picture element values. If the default font size in chrome is 16 px, 1 em = 16 pixels. One huge thought concerning Em is that it's relative to the font size of the parent component. As per the W3 specification, em is relative to the font size of the component on that they're used. Here we have done a beautiful job explaining the thought of em in an exceedingly clear and elaborated manner. If you actually wish to be told however em works, don't skip the higher than mentioned article. Ems area unit ordinarily used for typography like headings, texts, paragraphs, and also the parts related to typography like margins, padding, etc. If you set your base HTML and body parts font size in pixels and your typography element’s properties are outlined exploitation ems, for a responsive style all you wish to try and do is amend the default font size at the bottom level like

@media (max-width: 400px) {	 
    html, body { font-size: 15px; }	

and all em values can mechanically re-compute to the bottom level.

However, ems have a significant caveat, Inheritance!! as an example, a with a font size of 16px containing a with a font-size of 2em interprets to 32px for the component. Currently, add a within the with a font size of 0.5em too, the results of the div are 16px, half 32px, not 8px. This is often wherever rems get the image.


Unit = Font size of the element to be styled x Specified value of the element to be styled

Given a region component with a font size of 14px, after you produce a rule, with the padding property set to 3em, it'd appraise to 42px(14 x 3 = 42). This can be done no matter the font size allotted to the HTML component. Simply put, the font size of the component on that em unit is said to determine the picture element unit value.

Root Elements rem

Rem is relative to the font size of the basic component (HTML element). If the font size of the HTML component is 16px, then 1rem = 16px. Rem can invariably be relative to the basic component, no matter however nested the weather area unit. However, exploitation solely rems and no ems will have its own share of troubles because the typography will either become too huge or too tiny and this will result in scaling problems.

Let’s see an example: font-size of HTML component is 10px, paragraph is 1.6rem - 1.6rem * 10px = 16px.

Setting a root font size of 10px is that the commonest situation once I see folks utilizing REMs. It permits fast conversion between constituent values to REM values just by dividing the quantity by ten.

However, setting the bottom font size in constituents still has a constant downside because the pixel example is higher than. Accessibility overridden.

While REMs definitely have their uses, I’m willing to bet that the majority of folks use REMs as a result of they're seen as cooler than pixels. I seldom see a project wherever somebody really changes the basis hypertext markup language font-size betting on screen size; and truly thus. Unless you’ve got a really typographically serious style, you’re unlikely to need to scale everything right away.

What Is The Difference?

Pixel (px) could be a usually used CSS unit on websites. px is an absolute unit, it’s not scalable. Modification within the value of another component doesn't have an effect on the worth of absolute units. The worth appointed is mounted no matter the user setting.

Element (em) and Root component (rem) are responsive units understood into equivalent px units by the browser. They're relative units. Modification within the value of the parent or root component affects the worth of relative units. They scale with the device. So, what makes them different? The distinction lies in however the values are derived by the browser. To look at the computed values, go to the Chrome Developer Tools and open the Computed tab.

The computed pixel component value of the em unit is relative to the font size of the element being titled. This can be additionally tormented by transmissible values from the parent components unless it's expressly overridden by a px unit that isn't subject to inheritance.

The computed pixel component value of the rem unit is relative to the font size of the basis (HTML) element. this can be but tormented by the font size setting on the browser as a result of inheritance unless it's overridden by a px unit that isn't subject to inheritance.

Here Are Some Examples:

In most browsers, the default font size is 16px. Relative units calculate the dimensions from this base. If you alter that base by setting a base size for the HTML through CSS, then that becomes the premise for hard relative units calculations throughout the page. Similarly, if a user adjusts the font size, that then becomes the premise for hard relative units calculations.

So what is the meaning of these units once working with the default of 16px? 

The specified number will be multiplied by the default size. We have mentioned an example to make it more clear.

1em = 16px (1 * 16)
2em = 32px (2 * 16)
.5em = 8px (.5 * 16)
1rem = 16px
2rem = 32px
.5rem = 8px

Ok, this is done. However what if the default size is changed by some user? As a result of these being relative units, the ultimate size values are going to be primarily based on the new base size. Though 16px is the default size and if it is modified to 14px, then the calculation of the sizes would be like this:

1em = 14px (1 * 14)
2em = 28px (2 * 14)
.5em = 7px (.5 * 14)
1rem = 14px
2rem = 28px
.5rem = 7px

This gives the user the liberty to regulate her default browser font size, whereas the relative scale is still maintained for every part that is already specified.