PX to REM Converter

Convert between pixels and REM units for responsive CSS

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注意: 下記のツールインターフェースは現時点で英語のみに対応しています。UI の翻訳は順次進めています。 このツールを英語で見る →
Common sizes
PixelsREMSample
12px0.75remAa
14px0.875remAa
16px1remAa
18px1.125remAa
20px1.25remAa
24px1.5remAa
32px2remAa
40px2.5remAa
48px3remAa
64px4remAa

REM is relative to the root <html> font size - usually 16px by default. Using REM instead of PX means your layout scales when users change their browser text size.

使い方

  1. 1
    Set the base

    The default root font size is 16px - the browser default. Change it if your CSS overrides it.

  2. 2
    Type in either field

    Enter pixels or REM; the other updates instantly.

  3. 3
    Reference the table

    Common design-system sizes are pre-converted, with a visual preview of each font size.

PX to REM Converter について

Free online PX to REM converter. Type a pixel value to get the REM equivalent (or vice versa) based on your root font size. Includes a common-sizes table with live preview. Runs entirely in your browser. 712 Tools の PX to REM Converter はモダンな JavaScript API を使って完全にブラウザ内で動作します - サーバーがあなたのデータを見ることは一切ありません。つまり、即時の結果、完全なプライバシー、アップロード制限なしです。

デバッグ、簡単な確認、あるいは本番のインシデント対応まで - このツールは何度でも無料で使えます。ウォーターマークなし、サインアップなし、ツール内広告なし。

よくある質問

Why use REM instead of PX?

REM scales with the user's root font size - so users who bump their browser text size get a larger layout too. Better accessibility with no extra work.

What about EM?

EM is relative to the parent element's font size - useful for internal component scaling but confusing across a whole layout. REM is relative to the root only.

What if my root is 62.5%?

That's the 'REM = 10px' trick - set root font-size to 62.5% and 1rem = 10px. Change the base field to 10 in this tool.

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