REM 转 PX 转换器

What is REM to PX Converter?

REM to PX converter is a tool that transforms relative em (REM) units into pixels (PX). In web development, REM is a relative unit that refers to the font size of the root element (typically the element), while PX is an absolute unit. This converter helps developers maintain scalable and accessible designs while understanding the actual pixel values their REM units equate to.

When to Use REM to PX Converter

This converter is particularly useful in the following scenarios:

When designing responsive websites and you need to convert between relative and absolute units

When working with design systems that use REM units but you need pixel values for reference

When implementing designs from mockups that provide measurements in pixels, but you prefer coding with REM units

How to Calculate REM to PX

The conversion from REM to PX follows a simple formula:

PX = REM × Root Font Size

Where:

PX is the resulting pixel value

REM is the relative em value to convert

Root Font Size is the base font size of the html element (typically 16px by default in most browsers)

So given that the value of rem is relative on the root font-size. This means that if you assign 16px font-size on on your css, like this one:

html { font-size: 16px; }

This means that 1rem = 16px.

Examples

Basic REM to PX Conversion

Convert 1.5rem to pixels with the default root font size of 16px.

REM Value

Root Font Size

Calculation

Result

1.5rem

16px

1.5 × 16

24px

Converting Multiple REM Values

Convert 0.75rem, 2rem, and 3.5rem to pixels with a root font size of 16px.

REM Value

Root Font Size

Calculation

Result

0.75rem

16px

0.75 × 16

12px

2rem

16px

2 × 16

32px

3.5rem

16px

3.5 × 16

56px

Custom Root Font Size

Convert 2.5rem to pixels with a custom root font size of 20px.

REM Value

Root Font Size

Calculation

Result

2.5rem

20px

2.5 × 20

50px

Common REM to PX Conversion Table

Here's a reference table for common REM values converted to pixels (based on the default 16px root font size):

REM Value

Pixel Value

0.25 rem

4 px

0.5 rem

8 px

0.75 rem

12 px

0.875 rem

14 px

1 rem

16 px

1.125 rem

18 px

1.25 rem

20 px

1.5 rem

24 px

1.875 rem

30 px

2 rem

32 px

2.25 rem

36 px

2.5 rem

40 px

3 rem

48 px

4 rem

64 px

5 rem

80 px

Related Calculators

To explore more web development and design tools, check out these related calculators:

Aspect Ratio Calculator

Pixel Density Calculator