72 法則計算器

使用方法

1. 1
   填寫各項

   輸入數字或選擇所需選項。

2. 2
   檢視結果

   更改任何值時，答案會立即更新。

3. 3
   使用結果

   複製結果或記下來。不會向任何地方傳送任何內容。

About this tool

Enter an annual rate of return. The rule of 72 divides 72 by the rate to estimate the years to double. The tool also shows the exact result, and the rule of 114 and 144 for tripling and quadrupling.

The rule

Divide 72 by the interest rate to get the approximate years for money to double with compound interest. At 6 percent it takes about 12 years, at 9 percent about 8 years. It is accurate for rates between about 4 and 12 percent.

Why it matters

It shows how rates and time compound. It also works for inflation: at 3 percent inflation prices double in about 24 years.

Other versions

Use 114 for tripling and 144 for quadrupling. For very high or low rates, the exact formula is shown for comparison.

計算示例

With the boxes at their starting values (Annual rate of return (%): 7), the tool shows: Years to double (exact): 10.2; Years to triple (rule of 114): 16.3; Years to quadruple (rule of 144): 20.6; Years to double (rule of 72): 10.3. Change any box to see your own numbers. The result updates as you type, and nothing leaves your browser.

獲得最佳結果的提示

在相信結果之前先檢查每一個輸入項，因為一個錯誤的數字就會改變整個答案。請使用工資單、賬單、證書或合同上的準確數字，並記下計算日期。稅率、門檻和規則會不時變化，因此對於稅費和法律事務，請將結果視為估算，並與本頁註明的官方來源核對。您可以嘗試任意多個方案；不會儲存或傳送任何內容，重新整理頁面會清空輸入。