Visualmodo Tools
ToolsCSS Unit ConvertersREM to EM Converter
Responsive sizing utility for typography, spacing, layout tokens, and scalable UI systems

Instantly convert REM to EM and EM to REM.

A simple and fast tool to convert rem values to em units and back again for responsive web design. This canonical page covers both directions to avoid duplicate SEO pages for identical content.

Converter
Keep the base values on top, swap directions in one click, and convert between REM and EM in real time.

Bases

Configure only the reference values required for this conversion pair.

px
px

Conversion

Edit either side, copy any result, or swap the displayed direction.

REM

rem

EM

em

Canonical page shared by both directions: REM to EM and EM to REM.

Current conversion chart

A responsive visual curve based on the active direction and current base values.

1.5rem -> 1.5em
Live summary
Useful context while defining responsive and production-ready sizing systems.

Current conversion

1.5rem = 1.5em

Reverse conversion

1.5em = 1.5rem

Convert REM to pixels

Pixels = REM × Root Font Size

Convert pixels to EM

Result = Pixels / Parent Font Size

Context

  • Root font-size (base HTML): 16px
  • Parent font-size: 16px
How to Convert REM to EM
Canonical guidance that also applies to the reverse conversion on the same page.

Step 1: Define the relevant context

Confirm the values that influence the conversion. Relative units like REM, EM, VW, VH, and % depend on the root font-size, parent font-size, parent length, or viewport dimensions.

Step 2: Convert the source value into pixels

Normalize the source unit into pixels first. This gives you a consistent base for accurate conversion across all CSS unit types.

Pixels = REM × Root Font Size

Step 3: Convert pixels into the target unit

Once the intermediate pixel value is known, convert it into em using the target formula below.

Result = Pixels / Parent Font Size
Common REM to EM Reference
A quick reference table based on the current context values set above.
REMEM
0.25rem0.25em
0.5rem0.5em
0.75rem0.75em
0.875rem0.875em
1rem1em
1.125rem1.125em
1.25rem1.25em
1.5rem1.5em
2rem2em
3rem3em
4rem4em
4.5rem4.5em
6rem6em
REM to EM Converter Information
Background notes for design systems, responsive layouts, and frontend implementation.

Understanding REM

The rem unit scales from the root font-size of the document, making it a strong choice for accessible typography and consistent spacing systems.

Understanding EM

The em unit is relative to the current parent font-size, which makes it flexible for nested interface patterns and component-local scaling.

Why convert REM and EM?

  • System consistency: Work across design tokens, components, and documentation using a predictable translation between units.
  • Responsive control: Compare fixed, relative, and contextual units without guessing how they behave in production layouts.
  • SEO-safe structure: This page serves both directions of the same conversion pair to avoid duplicate content and consolidate relevance in one canonical destination.