PX to REM converter

PX to REM converter: uses and practical guidance

Choose the direction and enter the value and root font size in CSS pixels. Conversion from px to rem divides by the base; conversion back to px multiplies. For example, 24 px with a 16 px base equals 1.5 rem. The base must match the computed font size of html: 16 is an initial value rather than a browser or site guarantee. Negative values are accepted for margins and offsets, up to one million in absolute value. The base supports 0.01 to 1,000 px. Output uses a decimal point and up to six decimal places so you can copy the units into CSS. This does not convert physical pixels or em units.

PX to REM converter. Start with the example and observe the relationship between input and output before pasting a complete document. The example is deliberately small so that you can check it without another application. Then replace its data with a representative sample of your case and adjust the options. The main button performs the operation; loading the example only fills the controls. If you modify any input after calculating, the previous result is hidden so that you do not copy a version that no longer corresponds to the data. Run the operation again after every change. Clear restores the initial form values and discards the result on the page. Copy places the output text on the clipboard when the browser allows it. Download creates a file only when you explicitly request it; calculating does not start downloads. Keep a separate copy of the input if you need to repeat the work later, because this form is not a project archive and does not maintain an operation history.

PX to REM converter. Check a short sample whose result you can predict and another case containing the details that matter for your work. Inspect both the beginning and the end of the output; an apparently correct result may belong to an earlier input if you have saved several copies outside this page. If an error appears, reduce the sample until you find the offending data and review the stated limits. Do not remove information merely to dismiss a warning: first check whether the chosen operation represents what you need. Before using a download in another program, open it and inspect its characters, structure and values. The file contains the result rather than the form settings. If you need to explain how it was produced, retain the input and the options used as well.

A practical check before using the result

PX to REM converter. Convert CSS pixels and rem in either direction using your chosen root font size. Check the result before copying or downloading it.