Typography Converter
Convert Pixels, Points, REMs, EMs, and more.
CSS Unit Cheatsheet (Base 16px)
| Pixels (px) | EM / REM | Points (pt) | Percent (%) |
|---|---|---|---|
| 12px | 0.75rem | 9.0pt | 75% |
| 14px | 0.875rem | 10.5pt | 87.5% |
| 16px | 1rem | 12.0pt | 100% |
| 18px | 1.125rem | 13.5pt | 112.5% |
| 20px | 1.25rem | 15.0pt | 125% |
| 24px | 1.5rem | 18.0pt | 150% |
| 32px | 2rem | 24.0pt | 200% |
Web Typography
In responsive web design, using relative units like REM and EM is crucial for accessibility. They scale based on the user's browser settings.
Unit Explanations
Pixels (px)
Absolute unit relative to the viewing device. 1px = 1/96th of an inch.
REM (root em)
Relative to the font-size of the root element (html). Best for consistent sizing.
EM
Relative to the font-size of the element itself (or its parent). Good for padding/margins.
Points (pt)
Physical print unit. 1pt = 1/72 of an inch. 12pt is standard document text size.
Explore Design Tools
About Typography Converter
Modern web design relies on fluid and responsive units. Our Typography Converter is the ultimate tool for Front-End Developers to translate static design specs (typically in Pixels or Points) into scalable CSS units like REM and EM.
Mastering CSS Units
The Responsive Era (REM)
Relative Units are the standard for modern web development. Using `rem` allows the browser to scale the entire interface up or down based on the user's preference settings.
Best for: Font-Size, Margin, Padding
The Static Era (PX)
Absolute Units like pixels are rigid. While they offer pixel-perfect precision for borders or shadows, they fail accessibility standards for main text content because they ignore user zoom preferences.
Best for: Borders, Shadows, Min-Widths
Unit Breakdown
REM
Relative to root (html). The gold standard for accessibility.
EM
Relative to parent content. Good for components.
PT
1/72 of an inch. Legacy print unit.
%
Percent. Often used for fluid widths.
The Magic Number: 16px
Why is 16px so important? It is the browser default font size. Most REM calculations assume 1rem = 16px. However, developers often set html { font-size: 62.5% } (which is 10px) to make the math easier (1.4rem = 14px). Our tool supports custom base sizes to handle any reset strategy!
Frequently Asked Questions
Why should I use REM instead of PX?
Accessibility is the main reason. If you set a font size in px, it stays fixed even if the user changes their browser's default font size (e.g. for visual impairment). rem units scale relative to the root setting, ensuring your text remains readable for everyone.
What is the default base size?
In almost all modern browsers (Chrome, Firefox, Safari, Edge), the default root font size is 16px. This means 1rem = 16px. Our tool uses this as the default base, but you can adjust it if your CSS framework uses something different (like 10px or 14px).
What is the difference between EM and REM?
REM (Root EM) is relative to the <html> element. EM is relative to the parent element. This means em values compound (nesting a 1.2em text inside a 1.2em container makes it 1.44em), whereas rem is always consistent throughout the page. REM is generally safer for font sizes.
How do I calculate PX to REM manually?
The formula is: Pixels / Base Size = REM. For example, if you want 24px text and your base is 16px: 24 / 16 = 1.5rem. This converter just does that math instantly for you.
When should I use PT (Points)?
Points (pt) are primarily for Print Stylesheets (CSS for printing pages). Screens use a logical pixel grid, while printers use physical units (1 pt = 1/72 inch). You should almost never use points for on-screen web design.
Can I use percentages for font size?
Yes! 100% usually equals 1rem or 1em. A common pattern is setting html { font-size: 62.5%; }. This makes 1rem equal to 10px (since 62.5% of 16px is 10px), simplifying the math for developers who prefer thinking in base-10.
What are Viewport Units (vw/vh)?
Viewport units are relative to the screen size, not the font size. 1vw is 1% of the screen width. While great for large headlines, be careful using them for body text, as it can become unreadably small on mobile devices without clamp() functions.
Does using REM affect SEO?
Indirectly, yes! Google prioritizes Accessibility and Mobile Friendliness as ranking signals (Core Web Vitals). Using scalable units like REM improves accessibility scores (Lighthouse), which can boost your SEO rankings.
How do I switch my existing project to REMs?
You don't need to rewrite everything at once. Start by setting a base font size on the <body> (e.g., 1rem). Then, for new components or refactors, use this converter to translate your design system's pixel values into rems.
Are there tools to automate this?
Yes, there are PostCSS plugins (like postcss-pxtorem) that can automatically convert all px values in your CSS files to rem during the build process. However, manual conversion gives you more control over exactly which properties scale.