Debt Avalanche Calculator
Simulate the avalanche method: pay minimums on all, then throw the surplus at the highest-rate debt first — minimise total interest.
輸入資料
計算結果
重點速覽：Avalanche: pay each debt's minimum, then direct all leftover of a fixed total budget to the HIGHEST-rate debt first. Month by month: interest = balance x annual/12; pay minimums; apply surplus to highest rate; repeat until zero; sum months, total paid, total interest. Clearing one debt rolls its minimum into the next highest-rate target (keeping total constant) for acceleration. Mathematically minimises total interest and usually fastest. WARNING: Fixed rates, on-time, no new debt; may feel slow if the biggest debt is the highest rate. Education, not advice.
計算公式
維持每月總還款 = 各債務最低還款之和，過程不變。
每月各債務先計息：利息 = 餘額 × 年利率 ÷ 12。
先支付各債務最低還款，剩餘的總月供全數投放到『利率最高』的債務。
重複直至全部清還，累計月數、總還款與總利息。
$$\text{Interest}_i = \text{Balance}_i \times \dfrac{\text{Rate}_i}{12}$$$$\text{Budget} = \sum_i \text{MinPayment}_i \quad (\text{每月固定})$$$$\text{Surplus} \to \arg\max_i \text{Rate}_i \quad (\text{盈餘投放至利率最高者})$$使用說明
- Enter up to four debts' balances, rates and minimums.
- Enter a total monthly budget covering all minimums plus surplus.
- View months, total paid, total interest for the avalanche method.
同一組三筆債務 (總結欠 HK$46,000、總月供固定 HK$1,500) 以雪崩法 vs 滾雪球法的還款結果對照表
| 還款策略 | 還清月數 | 總利息支出 | 總還款額 |
|---|---|---|---|
| 雪崩 (優先利率最高) | 52 個月 | HK$31,749 | HK$77,749 |
| 滾雪球 (優先餘額最小) | 53 個月 | HK$32,152 | HK$78,152 |
| 雪崩較省 | 少 1 個月 | 少 HK$403 | 少 HK$403 |
以三筆債務實算:債務A 餘額 HK$4,000／年利率 6%／最低還款 HK$200，債務B 餘額 HK$30,000／年利率 30%／最低還款 HK$900，債務C 餘額 HK$12,000／年利率 18%／最低還款 HK$400，總月供固定 HK$1,500。每月各債務先計息 (餘額 × 年利率 ÷ 12)、先付最低還款，盈餘按策略投放，逐月模擬至清零，數字四捨五入至整數，僅供參考。可見雪崩法比滾雪球法省約 HK$403 利息、快 1 個月;差距大小視乎各筆債務的餘額與利率分佈。假設利率固定、每月準時還款，實際會因逾期或利率變動而不同。
理財情境案例
三筆債務用雪崩法：先攻 30% 大額卡數，總利息最低
陳小姐有三筆債務:一張小額卡數 HK$4,000 (年利率 6%、最低還款 HK$200)、一張大額高息卡數 HK$30,000 (年利率 30%、最低還款 HK$900)，以及一筆私人貸款 HK$12,000 (年利率 18%、最低還款 HK$400)，每月總還款固定 HK$1,500。
以雪崩法，她把盈餘全部投向年利率最高 (30%) 的大額卡數，讓最貴的利息最快停止累積。整體約 52 個月還清，總利息約 HK$31,749、總還款約 HK$77,749——是三種投放順序中利息最低的一條路徑。
雪崩 vs 滾雪球：同一組債務，省約 HK$403、快 1 個月
同一組三筆債務、同樣每月 HK$1,500，若改用滾雪球法 (先攻餘額最小的 HK$4,000 卡數)，約 53 個月還清、總利息約 HK$32,152。
兩相比較，雪崩法省約 HK$403 利息、快約 1 個月。若你的主要目標是把利息成本壓到最低，雪崩法通常是最佳選擇;但因高息債務未必是餘額最小的，初期較慢見到『少一筆數』的效果，需要較強的自律去堅持。
常見問題
How does the avalanche method work?
You pay every debt's minimum, then send all extra from a fixed total budget to the debt with the highest interest rate. Once that is cleared, you roll its old minimum into the next-highest-rate debt. Because you always hit the most expensive balance first, you minimise total interest and usually get debt-free fastest.
How does it differ from snowball?
Avalanche orders by interest rate (highest first) to save the most money; snowball orders by balance (smallest first) for psychological wins. Avalanche is mathematically optimal; snowball can be easier to stick with. Both require keeping the total monthly payment constant.
Why keep the total monthly payment constant?
Because the acceleration comes from rolling a cleared debt's minimum into the next target. If you divert the freed-up money elsewhere, you lose the speed and interest savings. Keep paying the same total every month.
How much can high-interest Hong Kong card debt cost?
Hong Kong credit-card revolving APRs commonly run ~20%-36%, far above personal loans. If you hold both high-rate card debt and lower-rate loans, avalanche clears the card first and can cut interest materially. Actual savings depend on balances, rate gaps and your available total budget.
What are the assumptions and data basis of this calculator?
It simulates month by month: each debt accrues interest (balance x annual rate / 12), minimums are paid first, and the fixed total budget's surplus goes to the highest-rate debt, repeating until all are cleared, tallying months, total paid and total interest. Avalanche/snowball are internationally recognised repayment concepts; for Hong Kong debt-management guidance see the Investor and Financial Education Council (IFEC). Results assume fixed rates and on-time monthly payments; for planning reference only.
相關工具
參考資料
內容審核：香港計算器財經團隊。還款過程採逐月計息模擬 (每月先計息、付最低還款，盈餘投放至利率最高者);雪崩策略屬國際通用還債概念，債務管理資訊參考投資者及理財教育委員會 (IFEC)，結果假設利率固定、每月準時還款，僅供參考。