Car Affordability Calculator
From your monthly payment budget, rate, term, cash and trade-in, work back to the maximum car price you can finance.
輸入資料
計算結果
重點速覽：Work backwards from an affordable monthly payment to the max car price. loan = payment / [r(1+r)^n / ((1+r)^n - 1)], r = rate/12, n = term x 12; max price = loan + cash + trade-in; total interest = payment x n - loan. Example: budget 6k/m, 5%, 5y, cash 80k, trade-in 20k → loan ≈ 318k, max price ≈ 418k, interest ≈ 42k. In Hong Kong, ownership also adds first registration tax, licence, insurance, fuel, parking. WARNING: Principal+interest only; keep payment within a safe income share (e.g. 20%) and leave room for other costs. Longer term lowers payment but raises interest. Education, not advice.
計算公式
可借貸款額 = 每月供款 × (1 − (1 + 月利率)^−期數) ÷ 月利率，月利率 = 年利率 ÷ 12。
最大可負擔車價 = 可借貸款額 + 可動用現金 + 舊車折抵。
總利息 = 每月供款 × 期數 − 可借貸款額。
$$L = M \times \dfrac{1 - (1+r)^{-n}}{r},\quad r = \dfrac{\text{annualRate}}{12}$$$$\text{MaxPrice} = L + \text{Cash} + \text{TradeIn}$$$$\text{Interest} = M \times n - L$$使用說明
- Enter the monthly payment you can afford.
- Enter the rate, term, cash down and trade-in.
- View the implied loan, max car price and total interest.
以每月供款 HK$5,000、年利率 5%、現金 HK$50,000、無舊車折抵為例，不同貸款年期對應的可借額、最大車價與總利息對照表
| 貸款年期 | 可借貸款額 | 最大可負擔車價 | 總利息 |
|---|---|---|---|
| 3 年 | HK$166,829 | HK$216,829 | HK$13,171 |
| 4 年 | HK$217,115 | HK$267,115 | HK$22,885 |
| 5 年 | HK$264,954 | HK$314,954 | HK$35,046 |
| 6 年 | HK$310,464 | HK$360,464 | HK$49,536 |
理財情境案例
月供多寡如何決定買得起的車價
李小姐手上有 HK$80,000 現金作首期，計劃 4 年車貸、年利率 5%，正比較不同月供水平能買多貴的車。
月供 HK$4,000:可借約 HK$173,692，最大車價約 HK$253,692;月供 HK$6,000:可借約 HK$260,538，最大車價約 HK$340,538;月供 HK$8,000:可借約 HK$347,384，最大車價約 HK$427,384。
月供由 4,000 增至 8,000 (翻倍)，可負擔車價亦大致翻倍。李小姐先按『所有債務月供不超月入三分之一』定出安全月供上限，再據此鎖定選車價位。
做法:先由收入與既有債務定出安全月供，再反推車價上限，比先看中車再硬湊供款更穩健。
別忘了養車的持續開支
陳先生用本計算器算出最大可負擔車價約 HK$267,115 (月供 5,000、4 年、5%、現金 5 萬)，正打算全數用盡買一部接近上限的車。
但購車只是開始 — 香港養車還有第一次登記稅、每年牌費、第三者/全保保險、泊車、燃油或充電、定期保養維修等，一年隨時多花數萬元。
若把車價買到上限，這些持續開支會壓垮每月現金流。穩健做法是預留車價上限的一部分緩衝，選略低於上限的車，讓月供加養車開支仍在可負擔範圍。
提醒:本計算器只算『買車』的可負擔上限，『養車』開支須另行預算並一併納入整體財務規劃。
常見問題
How does the budgeted payment drive the car price?
The calculator derives the loan you can service from the payment, then adds cash and trade-in to get the max car price. A higher budget, lower rate or longer term raises the price you can afford; a larger cash/trade-in also raises it directly. Always set the budget from your real cash flow, not the showroom's pitch.
What other car costs should I budget in Hong Kong?
Beyond the financed principal+interest, Hong Kong ownership adds first registration tax (based on taxable value, with a tiered rate and an EV concession), annual licence fee, compulsory third-party + own-damage insurance, fuel/electricity, parking and tolls. These can rival the finance cost, so budget the full monthly ownership cost, not just the instalment.
How much of my income should the payment be?
A common rule keeps total vehicle spending within about 20% of take-home pay, and the finance payment well under that. In high-cost Hong Kong, be conservative — a payment that looks fine can crowd out rent, MPF savings and emergencies. Test the payment against your full budget.
Does a longer term really help?
A longer term lowers the monthly payment and helps qualify for a pricier car, but total interest rises and you stay in debt longer. Often it is better to buy a cheaper car or save a bigger down payment than to stretch the term. Compare total interest across terms.
Is a trade-in worth it vs selling privately?
A trade-in is convenient and fast but usually nets less than a private sale. The convenience may be worth the gap for some; others sell privately to raise more down payment and lower the loan. Weigh the time/effort against the extra cash, and make sure the trade-in value is fairly stated against the new car's price.
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運輸署及投資者及理財教育委員會（IFEC）之相關指引，結果僅供參考，稅費及貸款條件實際以相關機構公佈為準。