Credit Card Payoff Calculator
From balance, APR and monthly payment, compute the months, total paid and total interest to clear the debt.
輸入資料
計算結果
重點速覽：Declining-balance method: monthly interest = balance x APR/12; next balance = balance + interest - payment, repeated until zero; sum months, total paid, total interest. More paid monthly = shorter term and less interest. If payment ≤ first-month interest, the balance grows forever (tool flags it). WARNING: simplified model; actual terms vary by issuer. Education, not advice.
計算公式
每月利息 = 餘額 × APR ÷ 12。
每月餘額 = 餘額 + 每月利息 − 每月還款額。
重複逐月計算，直至餘額歸零，累計月數、總還款與總利息。
若每月還款額 ≤ 首月利息，則永遠無法還清 (月數顯示為 0)。
$$B_{t+1} = B_{t} + B_{t}\times\dfrac{\text{APR}}{12} - \text{Payment}$$$$\text{Months} = \min\{\, t : B_{t} \le 0 \,\}, \quad \text{TotalPaid} = \text{Payment} \times \text{Months} - \text{last overpay}$$使用說明
- Enter the current balance.
- Enter the APR.
- Enter the monthly payment to see months and total interest.
結欠 HK$30,000 於不同 APR 與每月還款額下的還清月數與總利息
| 每月還款 | APR 24% | APR 30% | APR 36% |
|---|---|---|---|
| HK$1,000 | 47 個月／息 HK$16,273 | 57 個月／息 HK$26,144 | 78 個月／息 HK$47,900 |
| HK$1,500 | 26 個月／息 HK$8,696 | 29 個月／息 HK$12,108 | 31 個月／息 HK$16,498 |
| HK$3,000 | 12 個月／息 HK$3,811 | 12 個月／息 HK$4,960 | 13 個月／息 HK$6,203 |
以結欠 HK$30,000、逐月遞減餘額法實算，數字四捨五入至整數。信用卡實際還款會因逾期費用、利率變動及最低還款隨餘額調整而不同，僅供參考。
理財情境案例
每月多還一倍：57 個月縮短至 12 個月
以結欠 HK$30,000、APR 30% 為例:每月只還 HK$1,000，需約 57 個月 (近 5 年) 才清還，累積利息約 HK$26,144;若每月改還 HK$3,000，只需約 12 個月，累積利息驟降至約 HK$4,960。
還款期由 57 個月縮短至 12 個月，總利息減少約 HK$21,184 (省逾 8 成)。可見在能力範圍內盡量提高每月還款，是壓低信用卡利息、加快脫離卡數最有效的方法。
雪崩法 vs 雪球法：多卡還款怎樣排序？
同時持有多張卡數時，「雪崩法」先集中火力清還 APR 最高的卡 (其餘卡還最低額)，數學上總利息最少;「雪球法」則先還餘額最小的卡，較快「消卡」帶來成就感、易於堅持。
兩者都要求每月還款額高於各卡首月利息之和。若整體利率過高，可考慮把多張高息卡合併為一筆低息個人貸款 (債務重組)，或善用免息結餘轉戶優惠期，再配合本計劃逐月清還。
常見問題
Why can't the calculator show payoff months?
When the monthly payment is ≤ the first month's interest, the balance grows instead of shrinking and interest accrues without limit — it can never be cleared. Raise the monthly payment above the interest to start reducing principal.
How long does paying only the minimum take?
HK minimum payment is typically 'all interest and fees + at least 1% of principal', or ~HK$50, whichever higher. Because it barely exceeds interest, principal falls extremely slowly — repayment can stretch decades with total interest multiple times principal. The HKMA example uses ~2.5% monthly (≈35% effective annual).
Which is better, the avalanche or snowball method?
Avalanche pays the highest-APR card first (minimum on others) — least total interest, most money-saved. Snowball pays the smallest-balance card first — faster 'card killed' wins, easier to stay motivated. Both beat paying only the minimum.
What are fast ways to pay off?
Pay more than the minimum, target high-APR/small-balance cards, consolidate multiple high-rate cards into one lower-rate personal loan (debt restructuring), or use a 0% balance-transfer promo. Watch fees, lock-in and post-promo rates when refinancing.
Why does my result differ from the bank statement?
This is a simplified model (fixed APR, on-time payments, no annual/late fees). Actual statements vary with rate changes, late penalties and minimum payments that adjust with the balance. Use the statement as the final word.
相關工具
參考資料
內容審核：香港計算器財經團隊。計算邏輯與最低還款、循環利率資訊參考香港金融管理局（HKMA）「智醒消費者」及投資者及理財教育委員會（IFEC）之個人理財指引，結果僅供參考，實際以相關機構公佈為準。