Contribution Margin Calculator
From revenue and variable costs, compute the contribution margin and the contribution margin ratio.
輸入資料
計算結果
重點速覽：Contribution margin = revenue - variable cost; ratio = margin / revenue x 100%. It shows how much each revenue dollar covers fixed costs and profit. Example: revenue 100k, variable cost 60k → margin 40k, ratio 40% — use it to cover fixed costs, then profit. Unlike gross margin (deducts COGS), contribution margin deducts all variable costs (including variable selling/admin). WARNING: Correct variable/fixed split is essential; classification changes the result. Education, not advice.
計算公式
邊際貢獻 = 營業額 − 變動成本。
邊際貢獻率 = 邊際貢獻 ÷ 營業額 × 100%。
$$\text{Contribution Margin} = \text{Revenue} - \text{Variable Cost}$$$$\text{CM \%} = \dfrac{\text{Contribution Margin}}{\text{Revenue}} \times 100\%$$使用說明
- Enter the revenue for the period or batch.
- Enter the total variable costs.
- View the contribution margin and ratio.
以營業額固定為 HK$100,000 為例，變動成本由 HK$40,000 升至 HK$100,000 時的邊際貢獻與邊際貢獻率變化。
| 營業額 (HK$) | 變動成本 (HK$) | 邊際貢獻 (HK$) | 邊際貢獻率 |
|---|---|---|---|
| 100,000 | 40,000 | 60,000 | 60% |
| 100,000 | 60,000 | 40,000 | 40% |
| 100,000 | 80,000 | 20,000 | 20% |
| 100,000 | 100,000 | 0 | 0% |
理財情境案例
個案一：用邊際貢獻率算損益兩平
一間香港小型工作室每月固定成本 (租金加月薪) HK$60,000。其產品營業額 HK$100,000 時變動成本 HK$60,000，邊際貢獻率為 40%。
損益兩平營業額 = 固定成本 ÷ 邊際貢獻率 = 60,000 ÷ 40% = HK$150,000。即每月營業額要做到 HK$150,000 才剛好打平 (邊際貢獻 60,000 剛好覆蓋固定成本 60,000)，超過這個數才開始賺錢。這說明邊際貢獻率是計算損益兩平點的關鍵 — 率越高，達到兩平所需的營業額越低，安全邊際越大。
個案二：邊際貢獻為負的接單決策
一間工廠接到一張特價訂單，客戶只願付每件 HK$50，而該產品的變動成本 (原料加計件工資) 已達 HK$55。
此單的邊際貢獻 = 50 − 55 = −5 (負數)，代表每賣一件不但無法貢獻覆蓋固定成本，還會擴大虧損。這種訂單即使能『分攤固定成本』的說法也站不住腳 — 因為它連變動成本都收不回。因此除非有策略性考量 (如打入新客戶、清庫存)，否則邊際貢獻為負的訂單原則上應該拒絕。這正是邊際貢獻在接單與定價決策中的實用價值：它清楚劃出『接了會虧更多』的底線。
常見問題
What is the difference between contribution margin and gross margin?
Gross margin deducts COGS (which may include some fixed production cost like depreciation). Contribution margin deducts ALL variable costs (materials, piece-rate labour, commissions) and leaves every fixed cost to be covered by the margin. Gross margin is for financial reporting; contribution margin is for cost-behaviour and break-even decisions.
What is the contribution margin ratio used for?
It tells how much of each revenue dollar covers fixed costs and profit. Higher is safer. It is also the key to break-even: break-even revenue = fixed costs / contribution margin ratio.
What does a negative contribution margin mean?
Variable cost exceeds revenue — every sale loses money before fixed costs. Re-examine pricing or cost structure immediately; continuing only enlarges the loss.
How do I distinguish variable from fixed costs?
Variable costs move with output (materials, piece wages, commissions, packaging, usage-based utilities). Fixed costs stay roughly constant in the period (rent, salaried payroll, depreciation, insurance). Some are mixed and must be split; classification is relative to the period and capacity range.
How does this relate to Hong Kong SMEs?
For HK shops, F&B and studios, the contribution margin ratio drives break-even and pricing decisions (e.g. a studio with HK$60k fixed cost and 40% ratio needs HK$150k revenue to break even). Pair with the break-even and gross-margin calculators; the HKTDC and HKPC offer SME support. Education, not advice.
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。