📦 长方体表面积计算器（含体积）Surface Area of a Cuboid Calculator (with Volume)

使用说明与常见问题How-to & FAQ

「长方体表面积计算器（含体积）」是什么？What is the Surface Area of a Cuboid Calculator (with Volume) tool?

由长、宽、高求长方体表面积 2(lw + lh + wh) 和体积 lwh。边长须大于 0。本地处理。From length, width and height get the cuboid surface area 2(lw + lh + wh) and the volume lwh. Edges must be greater than 0. Processed locally.

如何使用「长方体表面积计算器（含体积）」？How do I use the Surface Area of a Cuboid Calculator (with Volume) tool?

在「长方体表面积计算器（含体积）」中，填写「长」、「宽」、「高」等参数，结果会随输入实时计算并显示在下方。In the Surface Area of a Cuboid Calculator (with Volume): Fill in "Length", "Width", "Height"; results are recalculated instantly as you type.

立方体怎么算？What about a cube?

三边相等时就是立方体：表面积 6a²，体积 a³。把长宽高都填成同一边长即可。When all three edges are equal it is a cube: surface 6a², volume a³. Enter the same value for length, width and height.

需要展开图吗？Do you show a net?

本页只给数值结果，不画展开图。This page only gives numeric results; it does not draw a net.

能举个计算实例吗？Can you show a worked example?

例如在「长方体表面积计算器（含体积）」中填 长 = 5，宽 = 3，高 = 2，结果区显示：表面积：62；体积：30For example, entering Length = 5, Width = 3, Height = 2 in the Surface Area of a Cuboid Calculator (with Volume) gives: Surface area: 62; Volume: 30

哪些输入会被检查？Which inputs are validated?

「长方体表面积计算器（含体积）」会检查这些输入——「长」：必须填写，须大于 0且不大于 1,000,000,000,000,000；「宽」：必须填写，须大于 0且不大于 1,000,000,000,000,000；「高」：必须填写，须大于 0且不大于 1,000,000,000,000,000；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 Surface Area of a Cuboid Calculator (with Volume) checks its inputs — "Length": required, must be more than 0 and at most 1,000,000,000,000,000; "Width": required, must be more than 0 and at most 1,000,000,000,000,000; "Height": required, must be more than 0 and at most 1,000,000,000,000,000; 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?

「长方体表面积计算器（含体积）」的设置：「长」默认 5；「宽」默认 3；「高」默认 2。每次生成结果都按当前设置处理。Settings in the Surface Area of a Cuboid Calculator (with Volume) — "Length" default 5; "Width" default 3; "Height" default 2. The result always uses the current settings.

计算精度如何？How precise are the results?

「长方体表面积计算器（含体积）」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 Surface Area of a Cuboid Calculator (with Volume) uses double-precision floating point (about 15–16 significant digits); very large or very small values may lose precision.

「长方体表面积计算器（含体积）」免费吗？需要注册吗？Is the Surface Area of a Cuboid Calculator (with Volume) free? Do I need an account?

「长方体表面积计算器（含体积）」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 Surface Area of a Cuboid Calculator (with Volume) is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.