📏 一拃 ↔ 掌Span to Palm
一拃与掌互算（1 span = 3 palm）。本地换算，附常用相关单位。Convert span and palm (1 span = 3 palm). Runs locally with related units.
点击任意一行可复制该结果；小于 0.0001 或不小于 10¹⁵ 的数值用 × 10ⁿ 科学计数法显示Click any row to copy that result. Values below 0.0001 or at least 10¹⁵ are shown in × 10ⁿ notation
使用说明与常见问题How-to & FAQ
「一拃 ↔ 掌」是什么？What is the Span to Palm tool?
一拃与掌互算（1 span = 3 palm）。本地换算，附常用相关单位。Convert span and palm (1 span = 3 palm). Runs locally with related units.
如何使用「一拃 ↔ 掌」？How do I use the Span to Palm tool?
在「一拃 ↔ 掌」中输入数值并选择原单位，表格会同时列出换算到所有其他单位的结果，可一键复制。Enter a value in the Span to Palm and choose the source unit; the table shows the value in every other unit at once, ready to copy.
1 一拃等于多少掌？How many palm in 1 span?
1 span = 3 palm（按国际定义系数）。1 span = 3 palm (international definition).
如何把一拃换算成掌？How do I convert span to palm?
结果 = 数值 × 3。例如 1 span = 3 palm。result = value × 3. Example: 1 span = 3 palm.
一拃/掌属于哪类单位？What kind of units are span/palm?
二者同属「长度」量纲，可安全互算；也可打开「length-converter」做多单位对照。Both are length units; see also the length converter hub.
换算系数准确吗？Are the conversion factors exact?
「一拃 ↔ 掌」采用国际单位制（SI）或公认标准中的定义值作为换算系数，结果保留约 10 位有效数字。The Span to Palm uses factors defined by the SI or other recognised standards and shows about 10 significant digits.
「一拃 ↔ 掌」免费吗？需要注册吗？Is the Span to Palm free? Do I need an account?
「一拃 ↔ 掌」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Span to Palm is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.