⏫ 翻倍时间计算器Doubling Time Calculator
按每期增长率计算数量翻倍所需时间 ln 2 ÷ ln(1 + r)，并与“72 法则”和“70 法则”估算比较；也可由起始值、结束值和经过时间反推增长率和翻倍时间。Find how long it takes something to double at a growth rate per period — ln 2 ÷ ln(1 + r) — compared with the Rule of 72 and Rule of 70, or work back from a start value, end value and elapsed time.
使用说明与常见问题How-to & FAQ
「翻倍时间计算器」是什么？What is the Doubling Time Calculator tool?
按每期增长率计算数量翻倍所需时间 ln 2 ÷ ln(1 + r)，并与“72 法则”和“70 法则”估算比较；也可由起始值、结束值和经过时间反推增长率和翻倍时间。Find how long it takes something to double at a growth rate per period — ln 2 ÷ ln(1 + r) — compared with the Rule of 72 and Rule of 70, or work back from a start value, end value and elapsed time.
如何使用「翻倍时间计算器」？How do I use the Doubling Time Calculator tool?
在「翻倍时间计算器」中，填写「已知」、「每期增长率 %」、「起始值」、「结束值」、「经过的期数」等参数，结果会随输入实时计算并显示在下方。In the Doubling Time Calculator: Fill in "Given", "Growth rate per period %", "Start value", "End value", "Periods elapsed"; results are recalculated instantly as you type.
翻倍时间公式？What is the doubling-time formula?
按期复利：T = ln 2 ÷ ln(1 + r)；连续复利：T = ln 2 ÷ r。r 为每期增长率（小数）。Per-period compounding: T = ln 2 ÷ ln(1 + r); continuous: T = ln 2 ÷ r, with r the growth rate per period as a decimal.
72 法则准吗？How accurate is the Rule of 72?
72 ÷ 增长率(%) 在 6%–10% 附近最准，例如 8% 时估算 9 期，精确值 9.006 期；增长率很高或很低时误差变大。70 法则更接近连续复利。72 ÷ rate (%) is most accurate around 6–10% — at 8% it gives 9 vs an exact 9.006 — and drifts at very high or low rates. The Rule of 70 is closer for continuous growth.
「翻倍时间计算器」免费吗？需要注册吗？Is the Doubling Time Calculator free? Do I need an account?
「翻倍时间计算器」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 Doubling Time 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.