🧊 长方体体积Volume of a Rectangular Prism
体积 V = 长 × 宽 × 高，并换算成升和立方英尺（按米输入时）；同时给出表面积。本地处理。Volume V = length × width × height, also in litres and cubic feet (for metre inputs), plus the surface area. Processed locally.
使用说明与常见问题How-to & FAQ
「长方体体积」是什么？What is the Volume of a Rectangular Prism tool?
体积 V = 长 × 宽 × 高，并换算成升和立方英尺（按米输入时）；同时给出表面积。本地处理。Volume V = length × width × height, also in litres and cubic feet (for metre inputs), plus the surface area. Processed locally.
如何使用「长方体体积」？How do I use the Volume of a Rectangular Prism tool?
在「长方体体积」中，填写「长」、「宽」、「高」、「单位」等参数，结果会随输入实时计算并显示在下方。In the Volume of a Rectangular Prism: Fill in "Length", "Width", "Height", "Unit"; results are recalculated instantly as you type.
容积和体积？Capacity vs volume?
容器内部能装的量叫容积，应按内壁尺寸计算。Capacity is what fits inside - use the inner dimensions.
能举个计算实例吗？Can you show a worked example?
例如在「长方体体积」中填 长 = 3，宽 = 4，高 = 5，单位 = 米，结果区显示：体积：60 m³；升：60,000 L；立方米：60 m³；表面积：94 m²For example, entering Length = 3, Width = 4, Height = 5, Unit = m in the Volume of a Rectangular Prism gives: Volume: 60 m³; Litres: 60,000 L; Cubic metres: 60 m³; Surface area: 94 m²
哪些输入会被检查？Which inputs are validated?
「长方体体积」会检查这些输入——「长」、「宽」、「高」：必须填写，须大于 0；绝对值超过 10¹⁵ 的数也会被拒绝。不符合时结果区显示具体提示，不会给出数字。The Volume of a Rectangular Prism checks its inputs — "Length", "Width", "Height": required, must be greater than 0; numbers above 10¹⁵ in absolute value are rejected too. When a value fails, the result area names the problem instead of showing a number.
有哪些选项可以调整？What options can I adjust?
「长方体体积」的设置：「长」默认 3；「宽」默认 4；「高」默认 5；「单位」可选 米、厘米、英寸、英尺（默认 米）。每次生成结果都按当前设置处理。Settings in the Volume of a Rectangular Prism — "Length" default 3; "Width" default 4; "Height" default 5; "Unit": m, cm, in, ft (default m). The result always uses the current settings.
计算精度如何？How precise are the results?
「长方体体积」使用 JavaScript 双精度浮点数（约 15–16 位有效数字）；极大或极小的数值可能存在精度误差。The Volume of a Rectangular Prism uses double-precision floating point (about 15–16 significant digits); very large or very small values may lose precision.
「长方体体积」免费吗？需要注册吗？Is the Volume of a Rectangular Prism free? Do I need an account?
「长方体体积」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 Volume of a Rectangular Prism is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.