PX to REM Converter
Convert CSS pixels and rem units in both directions using a configurable root font size.
Single Value
Common Conversions
How it works
Rem units are relative to the root element font size. With the default 16px base, 1rem equals 16px and 0.5rem equals 8px.
CSS Variables Helper
Generate CSS custom properties from pixel spacing values.
What is PX to REM Converter?
Convert CSS pixels and rem units in both directions using a configurable root font size. A pixel or rem value plus the root font size; optional comma-separated values for CSS variables. The converted value, common conversion references, and optional CSS custom-property declarations.
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What the tool does
- Input: A pixel or rem value plus the root font size; optional comma-separated values for CSS variables.
- Controls and processing: Direction switch between px→rem and rem→px; configurable base, defaulting to 16 px; CSS Variables Helper.
- Output: The converted value, common conversion references, and optional CSS custom-property declarations.
How to use it
- Provide the input. A pixel or rem value plus the root font size; optional comma-separated values for CSS variables.
- Review the settings. Direction switch between px→rem and rem→px; configurable base, defaulting to 16 px; CSS Variables Helper.
- Generate, inspect, and export. The converted value, common conversion references, and optional CSS custom-property declarations.
Key features
- Input: A pixel or rem value plus the root font size; optional comma-separated values for CSS variables.
- Controls and processing: Direction switch between px→rem and rem→px; configurable base, defaulting to 16 px; CSS Variables Helper.
- Output: The converted value, common conversion references, and optional CSS custom-property declarations.
Useful workflows
- Convert CSS pixels and rem units in both directions using a configurable root font size.
- Use it when you need this deliverable or diagnostic result: The converted value, common conversion references, and optional CSS custom-property declarations.
- Place it before the next verified workflow step: checking the generated values in the project’s actual root-size and zoom settings.
Limits and safety notes
- The formula is rem = px ÷ root font size. A 16 px default is common, not guaranteed; the actual computed root size can change through CSS and user settings.
Troubleshooting
- Use a plain numeric value and confirm the decimal separator, source/target unit, base or root size, DPI, and allowed range required by the page.
- Recalculate one known reference value, then compare assumptions and rounding before converting a list or applying the result in CSS or print.
- The formula is rem = px ÷ root font size. A 16 px default is common, not guaranteed; the actual computed root size can change through CSS and user settings.
Frequently asked questions
What is PX to REM Converter?
Convert CSS pixels and rem units in both directions using a configurable root font size.
How do I use PX to REM Converter?
Provide the expected input, review the page settings, then verify the result before copying or downloading it. Expected output: The converted value, common conversion references, and optional CSS custom-property declarations.
What input does it accept?
A pixel or rem value plus the root font size; optional comma-separated values for CSS variables.
What output does it produce?
The converted value, common conversion references, and optional CSS custom-property declarations.
What are the limits?
The formula is rem = px ÷ root font size. A 16 px default is common, not guaranteed; the actual computed root size can change through CSS and user settings.
Related AppKiro tools
Start with a verified input
Test with a small, non-sensitive sample, verify the key settings and output, then apply the result to the real workflow.
Open the tool