Balloon Payment Calculator
Work out the monthly instalment and the large final balloon payment for an amortising loan with a balloon term.
輸入資料
計算結果
重點速覽：A balloon loan amortises on a long schedule but is cleared early by a balloon. Monthly payment = amortised instalment over the full term; balloon = remaining principal at the balloon year (via the amortisation balance). Example: HK$1,000,000 at 5%, 30-year schedule, balloon at year 5 gives monthly ~HK$5,368 and balloon ~HK$912,900. WARNING: Plan to refinance or save for the balloon; failure to pay may mean default or loss of collateral. Hong Kong retail mortgages are mostly fully amortising, so read for any end-of-term lump sum.
計算公式
每月利率 i = 年利率 ÷ 100 ÷ 12。
月供 = A × i × (1+i)ⁿ ÷ ((1+i)ⁿ − 1)，n 為攤還總月數。
氣球尾款 = A × (1+i)^nb − 月供 ÷ i × ((1+i)^nb − 1)，nb 為氣球期月數。
總還款額 = 月供 × nb + 氣球尾款;總利息 = 總還款額 − 貸款額。
$$i = \dfrac{\text{annualRate}}{100 \times 12}, \quad n = \text{amortizationYears} \times 12, \quad n_b = \text{balloonYears} \times 12$$$$M = A \times \dfrac{i\,(1+i)^n}{(1+i)^n - 1}$$$$\text{Balloon} = A\,(1+i)^{n_b} - \dfrac{M}{i}\left[(1+i)^{n_b} - 1\right]$$使用說明
- Enter the loan amount and annual rate.
- Enter the amortisation term and the balloon year.
- View the monthly payment, the balloon, total repayment and interest.
以貸款 HK$100,000、年利率 7%、按 30 年攤還計算月供 (每月供款固定為 HK$665.30)，不同氣球期到期時的尾款與總利息比較。
| 氣球期 | 每月供款 | 期末氣球尾款 | 總還款額 | 總利息 |
|---|---|---|---|---|
| 3 年 | HK$665.30 | HK$96,726.96 | HK$120,677.85 | HK$20,677.85 |
| 5 年 | HK$665.30 | HK$94,131.59 | HK$134,049.74 | HK$34,049.74 |
| 7 年 | HK$665.30 | HK$91,147.41 | HK$147,032.82 | HK$47,032.82 |
| 10 年 | HK$665.30 | HK$85,812.38 | HK$165,648.68 | HK$65,648.68 |
理財情境案例
個案一:過渡性融資的低月供策略 (100 萬、5 年氣球)
梁小姐計劃買入一個商用單位作短期投資，預計 5 年內轉售。她借入 HK$100,000 作裝修週轉，年利率 7%、按 30 年攤還、5 年氣球到期。
計算結果:每月供款只需約 HK$665.30，5 年間現金流壓力極輕;但 5 年後單位售出時，須一次過清還氣球尾款約 HK$94,131.59。
由於她已鎖定買家、預期售價足以覆蓋尾款，這種結構讓她在持有期內保留最多現金作其他用途——但前提是退出計劃必須如期實現。
個案二:氣球期長短的取捨 (3 年 vs 10 年)
同樣借 HK$100,000、7% 息、30 年攤還，若氣球期選 3 年:總利息約 HK$20,678、尾款 HK$96,727;若拖長至 10 年:總利息暴增至 HK$65,649、尾款則降至 HK$85,812。
拉長氣球期雖然把尾款壓低約 HK$11,000，卻要多付近 HK$45,000 利息，並不划算。
教訓:氣球式貸款應搭配明確且短的退出時間表;若無法在短期內再融資或套現，長期只還利息、本金幾乎原封不動，總成本會遠高於一般全額攤還貸款。
常見問題
What is a balloon payment?
A large final lump-sum payment due at the end of a loan, while regular payments are based on a longer amortisation. It keeps monthly payments low but leaves a big balance to clear at the end.
Are balloon loans common in Hong Kong?
Hong Kong residential mortgages are mostly fully amortising, so pure balloon structures are rarer in retail mortgages. But they appear in commercial property loans, developer bridge finance, and some car or private loans with a 'balloon final payment'. Always check the contract for any end-of-term lump sum.
What if I cannot pay the balloon at maturity?
Commonly you 'refinance' — arrange a new loan before the balloon to clear it, effectively extending the loan. But refinancing success and rate depend on your credit, the property value and market rates at that time. If it fails and you lack cash, you may default or lose the collateral. Plan a backup before borrowing.
How is it different from interest-only?
Interest-only loans pay just interest each month and repay principal at the end in one go — effectively a 100% balloon. A balloon loan pays some principal monthly (lower payment than full amortisation) and a smaller-but-still-large balance at the end. Both leave an end lump sum; the difference is how much principal is chipped away monthly.
How do I compare the true cost?
Look beyond the low monthly payment: include the balloon, total interest to the balloon, and the refinancing risk. Compare the all-in cost and the APR, and stress-test whether you could cover the balloon from savings or a new loan. Do not pick a balloon just for a low monthly figure.
相關工具
參考資料
內容審核：香港計算器財經團隊。計算邏輯與公式參考香港金融管理局（HKMA）及投資者及理財教育委員會（IFEC）之個人理財計算指引，結果僅供參考，實際以相關機構公佈為準。