KS3 Cambridge Business: Formula & Theorem Quick Reference Handbook | KS3 剑桥商务：公式定理速查手册

📚 KS3 Cambridge Business: Formula & Theorem Quick Reference Handbook | KS3 剑桥商务：公式定理速查手册

This quick-reference handbook brings together all the essential formulas and key theorems you will encounter in the KS3 Cambridge Business course. From calculating profit and break-even points to interpreting liquidity ratios and exchange rates, the following sections provide a clear, bilingual summary. Each formula is presented with its English and Chinese versions side by side, making it easy to revise and memorise core concepts for topic tests and end-of-stage assessments.

这本速查手册汇总了KS3剑桥商务课程中所有重要的公式和关键定理。从计算利润和盈亏平衡点到解读流动性比率与汇率，以下各节提供了清晰的双语总结。每条公式均以英文和中文并列呈现，帮助你轻松复习并牢记核心概念，为期中测验和阶段末评估做好准备。

1. Revenue, Costs and Profit | 收入、成本与利润

Revenue is the total income a business generates from selling goods or services. Costs are the expenses incurred in producing those goods or services, and profit is what remains after all costs have been deducted from revenue. Understanding these three elements is the starting point for analysing any business’s financial health.

收入是企业通过销售商品或服务获得的总收入。成本是生产这些商品或服务所产生的支出，而利润是在从收入中扣除所有成本后剩余的部分。理解这三要素是分析任何企业财务健康的基础。

Revenue = Selling Price × Quantity Sold

收入 = 销售价格 × 销售数量

Fixed costs, such as rent and salaries, do not vary with output, while variable costs, like raw materials, change directly with the level of production. Total cost is the sum of all fixed and variable expenses.

固定成本（如租金和工资）不随产出变化，而可变成本（如原材料）则随生产水平直接变化。总成本是所有固定和可变支出的总和。

Total Costs = Fixed Costs + (Variable Cost per Unit × Quantity)

总成本 = 固定成本 + (单位可变成本 × 数量)

Profit is the reward for taking business risks. It can be reinvested to grow the business or distributed to owners.

利润是对承担商业风险的回报。它可以再投资以促进企业成长，或分配给所有者。

Profit = Revenue – Total Costs

利润 = 收入 – 总成本

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2. Contribution and Break-even Point | 单位贡献与盈亏平衡点

Contribution per unit tells us how much each item sold contributes towards covering fixed costs and then generating profit. The break-even point is the level of output where total revenue exactly equals total costs, meaning the business makes neither a profit nor a loss.

单位贡献告诉我们每售出一件商品在覆盖固定成本、继而产生利润方面贡献了多少。盈亏平衡点是指总收入恰好等于总成本的产量水平，即企业既不盈利也不亏损。

Contribution per Unit = Selling Price – Variable Cost per Unit

单位贡献 = 销售价格 – 单位可变成本

Once contribution per unit is known, the number of units needed to cover all fixed costs can be calculated. This break-even output is a vital planning tool.

知道了单位贡献后，就可以计算出需要多少产量来覆盖所有固定成本。这个盈亏平衡产量是一个重要的规划工具。

Break-even Output = Fixed Costs ÷ Contribution per Unit

盈亏平衡产量 = 固定成本 ÷ 单位贡献

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3. Margin of Safety | 安全边际

The margin of safety measures how much actual output or sales can fall before the business reaches its break-even point. A larger margin of safety indicates lower risk, as the business can withstand a drop in demand without slipping into a loss.

安全边际衡量在实际产出或销售下降多少后企业才会达到盈亏平衡点。安全边际越大，风险越低，因为企业可以承受需求下降而不至于陷入亏损。

Margin of Safety (units) = Actual Output – Break-even Output

安全边际（数量）= 实际产量 – 盈亏平衡产量

It can also be expressed in revenue terms by multiplying the unit figures by the selling price. A positive margin of safety means the business is operating profitably above the break-even level.

也可以用收入额表示，只需将数量乘以销售价格即可。正的安全边际意味着企业正在盈亏平衡水平以上盈利运营。

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4. Gross Profit and Net Profit | 毛利与净利

Gross profit focuses purely on trading performance by deducting the direct cost of goods sold from revenue. Net profit goes further and subtracts all other operating expenses, giving a fuller picture of overall profitability.

毛利仅关注销售表现，从收入中扣除已售商品的直接成本。净利则进一步扣减所有其他营业费用，更完整地展现整体盈利状况。

Gross Profit = Revenue – Cost of Sales

毛利 = 收入 – 销售成本

Cost of sales typically includes purchases and direct production expenses. After gross profit is calculated, businesses then deduct overheads such as rent, marketing and administrative costs to arrive at net profit.

销售成本通常包括采购和直接生产费用。计算出毛利后，企业再扣除租金、营销和行政管理等间接费用，得出净利。

Net Profit = Gross Profit – Expenses

净利 = 毛利 – 各项费用

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5. Profit Margins | 利润率

Profit margins express gross and net profit as a percentage of revenue, allowing for comparison between businesses of different sizes or across different time periods. Higher margins generally indicate better cost control and pricing power.

利润率将毛利和净利表示为收入的百分比，方便在不同规模的企业之间或不同时期之间进行比较。利润率越高，通常意味着成本控制和定价能力越强。

Gross Profit Margin = (Gross Profit ÷ Revenue) × 100%

毛利率 = (毛利 ÷ 收入) × 100%

The net profit margin after all expenses shows how much of each pound or dollar of sales eventually becomes profit for the owners.

扣除所有费用后的净利率则显示每英镑或每美元销售中有多少最终成为了所有者的利润。

Net Profit Margin = (Net Profit ÷ Revenue) × 100%

净利率 = (净利 ÷ 收入) × 100%

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6. Liquidity Ratios | 流动性比率

Liquidity ratios assess a business’s ability to meet its short-term debts using its current assets. The two most commonly used ratios at this level are the current ratio and the acid test (quick) ratio.

流动性比率评估企业利用流动资产偿还短期债务的能力。在这个阶段最常用的两个比率是流动比率和酸性测试（速动）比率。

Current Ratio = Current Assets ÷ Current Liabilities

流动比率 = 流动资产 ÷ 流动负债

A current ratio below 1 may indicate liquidity problems, whereas a very high ratio could mean too much cash is tied up unproductively. The acid test ratio removes inventories, which are often the least liquid current asset.

流动比率低于1可能表明存在流动性问题，而比率过高则可能意味着过多现金被低效占用。酸性测试比率剔除了存货，因为存货通常是流动性最差的流动资产。

Acid Test Ratio = (Current Assets – Inventories) ÷ Current Liabilities

速动比率 = (流动资产 – 存货) ÷ 流动负债

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7. Net Cash Flow | 净现金流

Cash flow is the movement of money into and out of a business over a specific period. Net cash flow shows whether more cash came in than went out, which is critical for day-to-day survival even if a business is profitable on paper.

现金流是指在特定时期内资金进出企业的变动情况。净现金流显示现金流入是否大于现金流出，这对日常生存至关重要，即使账面上盈利也可能出现问题。

Net Cash Flow = Total Cash Inflows – Total Cash Outflows

净现金流 = 现金流入总额 – 现金流出总额

A positive net cash flow means the business has generated extra cash to pay debts, invest or save. A negative figure calls for immediate attention to avoid running out of money.

净现金流为正意味着企业产生了额外现金，可用于还债、投资或储蓄。若为负值，则需要立即关注以避免资金耗尽。

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8. Interest Calculations | 利息计算

When a business borrows money or saves it in a bank account, interest is earned or charged. Simple interest is often used in KS3 to introduce the concept of borrowing and returns.

当企业借款或将钱存入银行账户时，会产生或赚取利息。KS3阶段通常使用单利来介绍借贷与回报的概念。

Simple Interest = Principal × Rate of Interest per annum × Time (years)

单利 = 本金 × 年利率 × 时间（年）

For example, borrowing £1,000 at 5% per year for 3 years would result in total interest of £1,000 × 0.05 × 3 = £150.

例如，以年利率5%借款1,000英镑，期限3年，总利息为1,000 × 0.05 × 3 = 150英镑。

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9. Exchange Rate Conversions | 汇率换算

Businesses trading internationally must convert money between currencies. The exchange rate tells you how much of one currency can be exchanged for a unit of another. Getting the conversion right prevents pricing errors.

从事国际贸易的企业必须在不同货币间兑换。汇率告诉你一单位某种货币可以兑换多少另一种货币。正确换算可以避免定价错误。

Amount in Currency B = Amount in Currency A × Exchange Rate (A to B)

B货币金额 = A货币金额 × 汇率（A兑换B）

To convert back, simply divide by the same exchange rate. If £1 = $1.25, then £100 becomes $125, and $125 becomes £100.

反向换算则除以相同的汇率即可。若1英镑 = 1.25美元，那么100英镑可换125美元，而125美元可换回100英镑。

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10. Labour Productivity | 劳动生产率

Labour productivity measures how efficiently a workforce turns inputs into outputs. Higher productivity can lead to lower costs per unit and greater profits, and it is often monitored when evaluating staff performance or investing in training.

劳动生产率衡量劳动力将投入转化为产出的效率。生产率提高可以降低单位成本、增加利润，在评估员工表现或投资培训时常常受到关注。

Labour Productivity = Total Output ÷ Number of Employees

劳动生产率 = 总产出 ÷ 员工人数

If a factory with 50 workers produces 5,000 units per week, labour productivity is 5,000 ÷ 50 = 100 units per worker. Comparing this figure over time helps managers identify trends and areas for improvement.

若一家工厂有50名工人，每周生产5,000件产品，则劳动生产率为5,000 ÷ 50 = 每名工人100件。通过比较不同时期的数据，管理者可以发现趋势和改进空间。

Published by TutorHao | Business Revision Series | aleveler.com

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