REM to PX Converter
Convert rem units to pixels (px) instantly, for CSS, design, and responsive layouts
I still remember the first time I tried to style a website and saw a rem unit in the CSS. I thought, what is this mysterious number and how many pixels does it actually mean? If you are a designer, developer, or just a CSS beginner, you have probably run into the same question. This is why I built this REM to PX Converter to make sizing in CSS as easy as pie.
No more guessing, no more trying to do math in your head. Just enter your rem value and the base font size, click convert, and you get the exact pixel value instantly.
What Are REM and PX in CSS?
REM stands for “root em,” and it is a relative unit in CSS. One rem equals the font size set on the root element of your page (usually html), often 16 pixels by default. It lets you create scalable, responsive layouts that are easy to read on any device.
PX is the classic pixel – one dot on your screen. Pixels are absolute, but rem units change if you change the base font size.
When you use rem, your layout becomes flexible and more user-friendly, but sometimes you need to know exactly how many pixels you are working with.
Why Convert REM to PX?
There are plenty of reasons for translating rem to px:
- You want to make sure your text and spacing look right on all devices
- You are working with a design that gives you pixel values, but your CSS uses rem
- You are checking if your rem values match a legacy px-based system
- You need to hand off sizes to a team or a client who is only familiar with pixels
This tool bridges the gap between responsive design and classic sizing.
What This Tool Does
The REM to PX Converter takes any rem value and a base font size, then instantly calculates the real pixel value. It works for decimals, large numbers, and even fractional rems. You just enter your numbers and get your answer, no calculator or mental math required.
All calculations happen in your browser, and nothing you type is ever sent or saved.
Input and Output Examples
Here are some everyday examples:
Example 1:
REM value:
2
Base font size:
16
Output:
32 px
Example 2:
REM value:
1.5
Base font size:
18
Output:
27 px
Example 3:
REM value:
0.875
Base font size:
20
Output:
17.5 px
You can use any combination, and this tool always gives you the pixel answer instantly.
How to Use This Tool (Step-by-Step)
- Type or paste your rem value into the REM Value box.
- Enter the base font size (in pixels) into the Base Font Size box. The default is 16.
- Click Convert REM to PX.
- Read your answer in the Pixel (PX) Output box.
- Copy and use the px value in your design, CSS, or documentation.
- Click Clear All to reset and start over.
You always get a clear, fast answer, and you can try as many times as you want.
What to Expect
You get roomy input boxes, instant feedback, and clear output. The tool works on every modern browser and phone, and keeps your data local for privacy. The design is simple, so you can focus on your work, not on fighting with interfaces.
Real-World Use Cases
- Web designers use this converter to make sure their layouts are pixel-perfect while keeping code scalable.
- Developers use it to migrate old px-based stylesheets to modern rem-based ones.
- Beginners use it to learn how different units affect their websites.
- Project managers and clients use it to double-check that their site matches the design files.
Why REM to PX Conversion Matters
With so many devices, screen sizes, and accessibility needs, using rem is a must for modern sites. But sometimes, pixels are still the standard for communicating size. This converter helps everyone stay on the same page, no matter what unit they prefer.
Frequently Asked Questions (FAQs)
What does this tool do?
This tool converts rem units to pixel (px) values, based on any base font size you choose.
What is the default base font size in most browsers?
Most browsers set the base font size to 16 px. You can change this in the tool if your project uses something else.
Can I use decimals or fractions for rem values?
Yes. The tool works for any number, including decimals and fractions.
What if my base font size is not 16?
Just enter your project’s root font size in the Base Font Size box. The answer will be accurate for your setup.
Can I convert px back to rem with this tool?
No. This tool is for rem to px. For the other direction, use our px to rem converter.
Is my data stored or uploaded anywhere?
No. All calculations are done in your browser and your numbers are never sent anywhere.
Does the tool work on mobile devices?
Yes. The converter is fully mobile-friendly.
Why should I use rem instead of px in CSS?
Rem makes your site more accessible and responsive, adjusting to user settings and devices. But knowing the px value helps with exact spacing and design.
Can I convert very large or small numbers?
Yes. The tool can handle any value you need for web design.
Is this tool free to use?
Yes. You can use it as much as you like, for free.