🧮 以 2 为底的对数Log Base 2 Calculator

使用说明与常见问题How-to & FAQ

「以 2 为底的对数」是什么？What is the Log Base 2 Calculator tool?

log₂(x) = ln(x)/ln(2)。可设置「x」。log₂(x) = ln(x)/ln(2). Settings: x.

如何使用「以 2 为底的对数」？How do I use the Log Base 2 Calculator tool?

在「以 2 为底的对数」中，填写「x」等参数，结果会随输入实时计算并显示在下方。In the Log Base 2 Calculator: Fill in "x"; results are recalculated instantly as you type.

以 2 为底的对数是什么意思？What does log base 2 mean?

log₂(x) 是 2 要乘方多少次才得到 x：2³ = 8，所以 log₂(8) = 3。本页按 ln(x) ÷ ln(2) 计算，x 必须大于 0。常用于比特数，例如 1024 种状态需要 log₂(1024) = 10 位。log₂(x) is the power you raise 2 to in order to get x: 2³ = 8, so log₂(8) = 3. The page computes ln(x) ÷ ln(2), and x must be above 0. It counts bits: 1,024 states need log₂(1024) = 10 bits.

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

例如在「以 2 为底的对数」中填 x = 8，结果区显示：log₂(x)：3；ln(x)：2.0794415417For example, entering x = 8 in the Log Base 2 Calculator gives: log₂(x): 3; ln(x): 2.0794415417

哪些输入会被检查？Which inputs are validated?

「以 2 为底的对数」会检查这些输入——「x」：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 Log Base 2 Calculator checks its inputs — "x": 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?

「以 2 为底的对数」的设置：「x」默认 8。每次生成结果都按当前设置处理。Settings in the Log Base 2 Calculator — "x" default 8. The result always uses the current settings.

计算精度如何？How precise are the results?

「以 2 为底的对数」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 Log Base 2 Calculator uses double-precision floating point (about 15–16 significant digits); very large or very small values may lose precision.

「以 2 为底的对数」免费吗？需要注册吗？Is the Log Base 2 Calculator free? Do I need an account?

「以 2 为底的对数」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 Log Base 2 Calculator is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.