3x Rent Income Rule Calculator
From the monthly rent and a multiple, work out the required gross monthly and annual income, split across tenants.
輸入資料
計算結果
重點速覽：The 3x rent rule is a common affordability guideline: landlords often require the tenant's gross monthly income to be at least three times the monthly rent. Formula: required monthly income = monthly rent x multiple (usually 3); required annual income = required monthly income x 12; per-tenant monthly income = required monthly income / number of tenants. It is equivalent to 'rent about one-third (33%) of gross income' as an affordability ceiling.
計算公式
所需月入 (合計) = 月租 × 收入倍數。
所需年入 (合計) = 所需月入 × 12。
每人所需月入 = 所需月入 ÷ 租客人數。
$$\text{所需月入} = \text{月租} \times \text{倍數}$$$$\text{租金收入比} = \dfrac{1}{\text{倍數}} \times 100\%$$使用說明
- Enter the monthly rent of the unit.
- Set the income multiple (usually 3) and the number of co-tenants.
- View the combined required gross monthly and annual income and the per-tenant average.
以月租 15,000 為例，不同倍數與租客人數下的所需稅前收入與租金收入比。
| 月租 | 倍數 | 租客人數 | 所需月入 (合計) | 每人月入 | 租金佔收入 |
|---|---|---|---|---|---|
| 15,000 | 3 | 1 人 | 45,000 | 45,000 | 33.3% |
| 15,000 | 3 | 2 人 | 45,000 | 22,500 | 33.3% |
| 15,000 | 2.5 | 1 人 | 37,500 | 37,500 | 40% |
| 15,000 | 3.3 | 1 人 | 49,500 | 49,500 | 30.3% |
理財情境案例
案例一：合租如何降低每人入息門檻
兩位年輕人想合租一個月租 HK$15,000 的單位。按 3 倍法則，這單位要求合計稅前月入 = 15,000 × 3 = HK$45,000 (年入 HK$540,000)。
由於是兩人合租，把合計收入分攤：每人只需月入 45,000 ÷ 2 = HK$22,500 即可達標。相比一人獨租需要月入 45,000，合租大幅降低了每人的入息門檻，這也是不少剛出社會的租客選擇合租的原因。
實務上各租客收入未必相同，只要合計收入達標，一般已符合大多數業主要求；但部分業主或代理可能要求每人各自達到某個比例，簽約前宜先問清楚。
案例二：由收入反推可負擔租金上限
一位月入 HK$36,000 (稅前) 的租客，想知道自己按 3 倍法則能租多貴的單位。反推：可負擔月租上限 = 月入 ÷ 倍數 = 36,000 ÷ 3 = HK$12,000。
若想更保守 (預留更多生活與儲蓄空間)，可用 3.3 倍：上限 = 36,000 ÷ 3.3 ≈ HK$10,900；若市場緊張、願意用較高比例，用 2.5 倍：上限 = 36,000 ÷ 2.5 = HK$14,400，但此時租金已佔收入 40%，財務彈性較小。
提醒：3 倍法則用『稅前』收入，且香港並無統一法定入息門檻，這只是可負擔能力的參考。租客實際還要扣除強積金、稅款與其他固定開支 (交通、保險、家庭供養)，建議把租金控制在稅後收入的合理比例，避免『租金達標』卻月月拮据。
常見問題
Should I use gross or net income?
The 3x rule uses gross (pre-tax) income — total income before tax and deductions. Compare on gross monthly income, not the net amount actually received.
Is there a statutory rent income rule in Hong Kong?
No unified statutory threshold. The 3x rule originates from overseas (especially US/European) rental markets, and local landlords and agents vary in whether and how they apply it. This tool is a personal affordability and budgeting reference, not a binding rule.
How does co-tenancy work?
Enter more than 1 tenant and the calculator splits the combined required income evenly. In practice incomes may differ; as long as the combined income meets the threshold, most landlords are satisfied.
What income proof is needed to rent in Hong Kong?
Although there is no unified threshold, landlords or agents commonly ask for proof of income such as recent bank statements, pay slips, tax returns (tax assessment notices) or employer letters; self-employed applicants may need company financials or tax documents. This rule is mainly a budgeting reference to check affordability before applying.
What rent share is safe, and how does it relate to 50/30/20?
The 3x rule implies rent about 33% of gross income — a common affordability ceiling. It is close to the popular 50/30/20 budget: roughly 50% of net income to 'needs' (rent being the largest), 30% to wants, 20% to savings and debt. In pricey Hong Kong, keeping rent at or below 30% of gross, with room to save after fixed costs, is the more prudent aim.
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。