Average Variable Cost (AVC) Calculator
From total variable cost and output, compute the average variable cost per unit (AVC).
輸入資料
計算結果
重點速覽：AVC = total variable cost / quantity. Variable costs vary with output (materials, piece-rate wages, packaging, metered utilities); fixed costs do not. AVC is the short-run shutdown-point benchmark — produce only if price covers AVC. AVC + AFC = ATC. WARNING: AVC is typically U-shaped; this is an average at a single output, not marginal cost; the variable/fixed split is context-dependent.
計算公式
AVC = 總可變成本 ÷ 產量。
$$AVC = \dfrac{\text{總可變成本 (TVC)}}{\text{產量 (Q)}}$$$$ATC = AVC + AFC \quad (\text{平均總成本} = \text{平均可變成本} + \text{平均固定成本})$$使用說明
- Enter the total variable cost for the period.
- Enter the output quantity.
- View the average variable cost per unit.
總可變成本固定為 HK$200,000 時，不同產量對應的平均可變成本
| 產量 | 總可變成本 | 平均可變成本 (AVC) | 解讀 |
|---|---|---|---|
| 2,000 件 | HK$200,000 | HK$100.00 | 產量低，每件攤高 |
| 5,000 件 | HK$200,000 | HK$40.00 | 本工具預設值 |
| 8,000 件 | HK$200,000 | HK$25.00 | 規模上升、單位成本下降 |
| 10,000 件 | HK$200,000 | HK$20.00 | 接近規模效益 |
| 20,000 件 | HK$200,000 | HK$10.00 | 產量倍增、AVC 減半 |
理財情境案例
案例一：算出每件的平均可變成本
某工廠某月總可變成本 HK$200,000 (原材料、計件工資、包裝)，產量 5,000 件。AVC = 200,000 ÷ 5,000 = HK$40 / 件。
這代表每多生產一件產品，平均增加 HK$40 的可變成本，是定價與接單決策的重要下限參考。
案例二：用 AVC 判斷是否接低價急單
同一工廠收到一張急單，客戶只願出價每件 HK$35，而目前售價 HK$60。由於 HK$35 低於 AVC HK$40，這張單連可變成本都收不回，每做一件都在淨虧損。
若產能有閒置且不影響正價訂單，理論上只有售價高於 AVC 才值得接;低於 AVC 應婉拒，否則越做越蝕。這正是 AVC 作為『短期停業點』的實際應用。
常見問題
How do I split variable and fixed costs?
Variable costs move with output — more production means a larger total (materials, piece wages, packaging, metered utilities). Fixed costs stay broadly constant within a range (rent, management salaries, depreciation). The split is not absolute: over a longer horizon or a big capacity expansion, many 'fixed' costs also move. Judge by the decision's time horizon.
What is the link between AVC and the shutdown point?
In the short run, if the selling price exceeds AVC, each unit sold covers variable cost and contributes toward fixed cost, so producing is better than stopping. If price falls below AVC, you cannot even recover variable cost and lose more by producing — shutting down minimises loss. So AVC is the economics 'shutdown point'.
Can I use AVC directly for pricing?
AVC is only a pricing floor, not a standalone price. A proper price must also cover average fixed cost (AVC + AFC = ATC), add target profit, and consider demand and competition. Pricing at AVC alone leaves fixed costs unrecoverable and the business loses money long term. AVC is better for short-run capacity and order decisions (e.g. whether to accept a low-ball urgent order).
How is AVC different from marginal cost (MC)?
AVC is an 'average' (total variable cost / total output); MC is 'incremental' (cost of one more unit). They differ: when MC < AVC, making one more unit pulls the average down; when MC > AVC, AVC rises. The AVC U-shape's minimum is where MC crosses AVC. For order decisions, strictly look at MC; where cost is stable and roughly proportional, AVC is a practical proxy.
How does AVC change with output (why U-shaped)?
In the short run AVC is usually U-shaped. At low output, plant and labour are underused and there is a learning effect, so unit variable cost is high; as output rises, specialisation and scale lower it into a trough; near capacity, overtime, machine strain and material premiums push marginal cost up and AVC rises again. This tool computes the average at one output; to see the U-shape, enter the actual total variable cost at different outputs, not a fixed total.
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。