📚 IGCSE AQA Accounting: Quick Reference Formula & Theorem Handbook | IGCSE AQA 会计：公式定理速查手册
This handbook is designed to give IGCSE AQA Accounting students rapid access to every essential formula, theorem and key principle needed for success. Each section presents the core relationship, the rationale behind it, and a worked example where helpful, so you can move from memorisation to confident application.
本手册旨在为 IGCSE AQA 会计考生提供所有核心公式、定理和关键原则的速查。每一节都给出基本关系、背后的原理，并在必要时辅以简单示例，帮助你从单纯记忆走向自信运用。
1. The Accounting Equation & Double-Entry Principle | 会计恒等式与复式记账原则
The accounting equation is the foundation of the entire double-entry system. It must hold true after every transaction.
会计恒等式是整个复式记账体系的基础。每笔交易发生后，该等式必须依然成立。
Assets = Liabilities + Owner’s Equity
资产 = 负债 + 所有者权益
The double-entry principle states that every business transaction affects at least two accounts, with total debits always equal to total credits. Debit (Dr) increases assets and expenses, credit (Cr) increases liabilities, capital and income.
复式记账原则要求每笔交易至少影响两个账户，且借方总额永远等于贷方总额。借记 (Dr) 增加资产和费用，贷记 (Cr) 增加负债、资本和收益。
- Purchase of goods on credit → Dr Purchases, Cr Trade Payables
- 赊购商品 → 借记采购，贷记应付账款
- Cash sale → Dr Cash, Cr Sales
- 现金销售 → 借记现金，贷记销售收入
- Owner introduces capital → Dr Bank, Cr Capital
- 业主投入资本 → 借记银行存款，贷记资本
The accounting equation also helps in preparing the statement of financial position: net assets (total assets − total liabilities) must equal total equity.
会计恒等式也用于编制财务状况表：净资产（总资产−总负债）必须等于总权益。
2. Profit Calculation: Cost of Sales, Gross Profit & Net Profit | 利润计算：销售成本、毛利与净利
A clear understanding of the profit structure is vital. The income statement follows a strict chain of relationships.
清晰理解利润结构至关重要。损益表遵循严格的递推关系。
Net Sales = Total Sales − Sales Returns
净销售额 = 总销售额 − 销售退回
= Opening Inventory + Purchases − Purchase Returns + Carriage Inwards − Closing Inventory
销售成本 = 期初存货 + 采购 − 采购退回 + 购货运费 − 期末存货
Gross Profit = Net Sales − Cost of Sales
毛利润 = 净销售额 − 销售成本
Net Profit = Gross Profit + Other Income − Expenses
净利润 = 毛利润 + 其他收益 − 费用
Remember that carriage inwards is a trading cost and forms part of cost of sales, while carriage outwards is a selling expense deducted below the gross profit line.
注意：购货运费属于采购成本，计入销售成本；销货运费则是销售费用，在毛利之下扣除。
Expenses typically include rent, wages, advertising, depreciation, irrecoverable debts and allowances for receivables. Accruals and prepayments must be adjusted first to reflect expenses incurred, not merely paid.
费用通常包括租金、工资、广告费、折旧、坏账及坏账准备。必须首先调整应计和预付款项，以反映实际发生的费用，而非仅支付的金额。
3. Depreciation Methods | 折旧方法
Depreciation allocates the cost of a non-current asset over its useful life. AQA requires both straight-line and reducing balance methods.
折旧是将非流动资产在其使用寿命内分摊成本。AQA 考试要求掌握直线法和余额递减法。
Straight-line annual depreciation = (Cost − Residual Value) ÷ Useful Life (years)
直线法年折旧额 = (成本 − 预计残值) ÷ 使用年限
Under the straight-line method, the same amount is charged each year. The net book value (NBV) at year-end is cost minus accumulated depreciation.
直线法下，每年计提的折旧额相同。年末账面净值 (NBV) 等于成本减去累计折旧。
Reducing balance annual depreciation = NBV at start of year × Depreciation Rate (%)
余额递减法年折旧额 = 年初账面净值 × 折旧率 (%)
The reducing balance method charges a higher expense in early years. The rate remains constant but is applied to a decreasing NBV. Residual value is not subtracted annually; instead, depreciation stops when NBV reaches the scrap value.
余额递减法在早期计提更多折旧。折旧率保持不变，但应用于逐期递减的账面净值。每年不扣除残值；当账面净值降至残值时，停止计提折旧。
Both methods affect profit and the carrying amount of assets on the statement of financial position. The choice of method depends on the pattern of benefits consumed.
两种方法都会影响利润和财务状况表中资产的账面价值。方法的选择取决于所消耗经济利益的模式。
4. Profitability Ratios | 盈利能力比率
Profitability ratios measure how effectively a business generates profit from its resources. They are critical for decision-making and comparison over time or with competitors.
盈利能力比率衡量企业利用资源创造利润的效率。它们对于决策以及跨期或同业比较至关重要。
Gross Profit Margin = (Gross Profit ÷ Revenue) × 100%
毛利率 = (毛利润 ÷ 营业收入) × 100%
This ratio indicates the proportion of sales revenue remaining after covering the cost of inventory sold. A decline may signal rising purchase costs or stock losses.
该比率反映销售收入在弥补已售存货成本后剩余的比例。比率下降可能预示采购成本上升或存货损失。
Net Profit Margin = (Net Profit ÷ Revenue) × 100%
净利率 = (净利润 ÷ 营业收入) × 100%
Net profit margin shows overall efficiency after controlling operating expenses. A high net margin relative to gross margin suggests tight expense control.
净利率显示控制营业费用后的整体效率。相对于毛利率较高的净利率表明费用控制得力。
Return on Capital Employed (ROCE) = (Operating Profit ÷ Capital Employed) × 100%
已用资本回报率 (ROCE) = (营业利润 ÷ 已用资本) × 100%
Capital employed is usually defined as non-current assets plus net current assets (working capital) or, equivalently, total equity plus non-current liabilities. ROCE is a fundamental measure of how well the business uses its long-term funding.
已用资本通常定义为非流动资产加净流动资产（营运资金），或等于总权益加非流动负债。ROCE 是衡量企业运用长期资金效果的根本性指标。
5. Liquidity Ratios | 流动性比率
Liquidity ratios assess a firm's ability to meet short-term obligations as they fall due. They focus on current assets and current liabilities.
流动性比率评估企业偿还到期短期债务的能力，重点关注流动资产和流动负债。
Current Ratio = Current Assets ÷ Current Liabilities
流动比率 = 流动资产 ÷ 流动负债
A current ratio of between 1.5 and 2.0 is often regarded as healthy, though it varies by industry. Too high a ratio may indicate under-utilisation of assets, while too low a ratio may signal a liquidity crisis.
通常认为 1.5 至 2.0 的流动比率较为健康，但依行业而异。过高可能意味着资产未充分利用，过低则可能预示流动性危机。
Quick Ratio (Acid Test) = (Current Assets − Inventory) ÷ Current Liabilities
速动比率 (酸性测试) = (流动资产 − 存货) ÷ 流动负债
The quick ratio excludes inventory because it is the least liquid current asset. A ratio of around 1:1 is generally considered satisfactory. Both ratios should be read together.
速动比率扣除存货，因为存货是流动性最差的流动资产。该比率接近 1:1 通常较为理想。两种比率应结合解读。
6. Efficiency Ratios | 营运效率比率
Efficiency ratios show how well a business manages its inventory, receivables and payables. They convert statement figures into days or times, giving a clear picture of working capital management.
营运效率比率反映企业管理存货、应收账款和应付账款的能力，将报表数据转化为天数或次数，清晰展示营运资金管理状况。
Inventory Turnover (times) = Cost of Sales ÷ Average Inventory
存货周转率 (次数) = 销售成本 ÷ 平均存货
nventory + closing inventory) ÷ 2. A higher turnover generally indicates efficiency, but very high turnover may risk stock-outs.
其中平均存货 = (期初存货 + 期末存货) ÷ 2。周转率较高通常意味着效率，但过高可能导致断货风险。
Trade Receivables Turnover (Days) = (Trade Receivables ÷ Credit Sales) × 365
应收账款周转天数 = (应收账款 ÷ 赊销收入) × 365
This ratio tells the average number of days it takes to collect cash from credit customers. A high number suggests poor credit control or slow collection.
该比率表示从赊销客户收回现金的平均天数。天数较高表明信用控制不力或收款缓慢。
Trade Payables Turnover (Days) = (Trade Payables ÷ Credit Purchases) × 365
应付账款周转天数 = (应付账款 ÷ 赊购金额) × 365
If credit purchases are not available, cost of sales can sometimes be used as an approximation. A longer payables period can ease liquidity but may strain supplier relations.
若无法获取赊购金额，有时可用销售成本近似代替。付款期限较长可以缓解流动性，但也可能影响供应商关系。
7. Bank Reconciliation Formulas | 银行调节表公式
A bank reconciliation statement matches the corrected cash book balance with the bank statement balance after adjusting for timing differences and errors.
银行调节表在调整时间性差异和错误后，将更正后的现金簿余额与银行对账单余额进行核对。
Start with the cash book balance, add or subtract items not yet recorded in the bank statement (e.g. direct debits, bank charges, interest, dishonoured cheques) to obtain the adjusted cash book balance.
从现金簿余额出发，加减银行对账单尚未记录的项目（如直接借记、银行手续费、利息、拒付支票等），得到调整后的现金簿余额。
Then take the bank statement balance, add uncredited deposits (lodgements not yet credited), subtract unpresented cheques, and correct any bank errors. The final figure should equal the adjusted cash book balance.
再取银行对账单余额，加上未贷记存款（尚未入账的存款），减去未兑现支票，并更正任何银行错误。最终金额应等于调整后的现金簿余额。
| Bank Statement Balance | £ |
|---|---|
| Add: Uncredited deposits | X |
| Less: Unpresented cheques | (X) |
| Add/Less: Bank errors | X/(X) |
| Balance as per cash book (updated) | X |
This structured approach ensures that all differences are identified and the cash book is corrected for accurate future reporting.
这一结构化方法确保所有差异均已识别，现金簿得到更正，以便后续准确报告。
8. Correction of Errors & Suspense Account | 纠正错误与暂记账户
When a trial balance does not balance, the difference is temporarily entered into a suspense account. However, not all errors are revealed by a trial balance.
当试算表不平衡时，差额会暂时计入暂记账户。然而，并非所有错误都可通过试算表发现。
Types of errors include:
错误类型包括：
- Error of omission – a transaction is completely missed → Dr and Cr omitted
- 遗漏错误 – 交易完全遗漏 → 借方和贷方均遗漏
- Error of commission – recorded in the wrong account of the same class (e.g. wrong customer's account)
- 账户记错 – 记入同一类别的错误账户（如记错客户）
- Error of principle – a capital item treated as revenue (e.g. purchase of vehicle debited to purchases)
- 原则性错误 – 资本性支出误作收益性支出（如购车借记采购账户）
- Compensating error – two errors of equal amount cancel each other
- 抵消错误 – 两笔等额错误相互抵消
- Error of original entry – wrong amount entered on both sides
- 原入账错误 – 借贷双方均以错误金额入账
- Complete reversal of entries – Dr and Cr swapped
- 完全颠倒分录 – 借贷方向错误
Errors that affect the trial balance require a suspense account. The entry to clear the suspense must reverse the original error and then record the correct transaction.
影响试算平衡的错误需要通过暂记账户处理。清除暂记的分录必须先冲销原错误，再记录正确交易。
For example, if sales of £500 were only credited to sales and not debited to cash, the trial balance credits exceed debits by £500. The suspense account is credited £500. To correct: Dr Suspense £500, Cr Cash £500 (assuming cash sale omitted). The suspense account then closets to zero.
例如，一笔 £500 的销售仅贷记销售收入而未借记现金，导致试算表贷方比借方多 £500。暂记账户贷记 £500。更正分录：借记暂记 £500，贷记现金 £500。暂记账户归零。
9. Accruals & Prepayment Adjustments | 应计与预付款项调整
The accruals concept requires income and expenses to be matched to the period in which they are earned or incurred, not when cash is received or paid.
应计概念要求收入和费用与其赚取或发生的期间相匹配，而非以现金收付为准。
For expenses, the adjusted amount charged to the income statement is:
对于费用，计入损益表的调整后金额为：
the year + Closing Accruals − Opening Accruals + Opening Prepayments − Closing Prepayments
当年费用 = 当年支付额 + 期末应计 − 期初应计 + 期初预付款 − 期末预付款
An accrual arises when an expense is incurred but not yet paid. It is recorded as an increase in expense and a current liability.
应计费用产生于费用已发生但尚未支付时，记录为增加费用和一项流动负债。
A prepayment occurs when a payment is made in advance. It is recorded as a decrease in expense (or an asset) and a reduction in the amount charged to the current period.
预付款项指提前支付的款项，记录为费用减少（或确认为资产），减少当期应计费用。
d + closing income accrued − opening income accrued + opening income prepaid − closing income prepaid. These adjustments ensure the financial statements reflect the true performance and position.
对于收入（如房租或佣金收入），逻辑相同：当期收入 = 收到金额 + 期末应计收入 − 期初应计收入 + 期初预收收入 − 期末预收收入。这些调整确保财务报表反映真实的业绩和状况。
10. Disposal of Non-current Assets | 非流动资产处置
When a non-current asset is sold, a disposal account is used to calculate the profit or loss on sale. The relevant formulas are:
当出售非流动资产时，使用处置账户计算处置损益。相关公式如下：
Net Book Value (NBV) at disposal = Cost − Accumulated Depreciation to date of disposal
处置时账面净值 (NBV) = 成本 − 截至处置日的累计折旧
If the asset was part-way through the year, depreciation must first be brought up to date. Then transfer the cost and accumulated depreciation to the disposal account.
若资产在年度中间处置，需先补提当年折旧。然后将成本和累计折旧转入处置账户。
Profit (Loss) on Disposal = Sale Proceeds − NBV
处置损益 = 出售所得 − 账面净值
A credit balance on the disposal account indicates a profit (income), while a debit balance indicates a loss (expense). This figure is transferred to the income statement.
处置账户出现贷方余额表明盈利（收益），借方余额表明亏损（费用）。该金额结转至损益表。
Remember that the asset must be removed from the non-current asset register and that any part-exchange allowance follows the same logic: treat the allowance as part of the proceeds.
注意，资产必须从非流动资产登记簿中移除，任何以旧换新折让均视同处置所得处理。
11. Financial Position & Working Capital | 财务状况与营运资金
The statement of financial position reflects the accounting equation and shows the sources and uses of funds. A key subtotal is working capital.
财务状况表反映会计恒等式，展示资金来源和运用。其中一个重要小计是营运资金。
Working Capital = Current Assets − Current Liabilities
营运资金 = 流动资产 − 流动负债
Positive working capital indicates the business can cover short-term debts. A consistent negative figure may signal insolvency risk.
营运资金为正表明企业能够偿还短期债务。持续为负则可能预示偿债风险。
Net assets (total assets − total liabilities) should equal the equity section, which comprises opening capital + capital introduced + net profit − drawings (for sole traders).
净资产（总资产−总负债）应等于权益部分，后者包括期初资本 + 追加资本 + 净利润 − 提款（适用于个体经营者）。
12. Quick Check: Ratio Interpretation Guide | 快速查阅：比率解读指南
The table below summarises the ideal movement for key ratios. Remember that context matters, and these are general indicators only.
下表概括了关键比率理想的变化方向。请注意，解读须结合具体情况，以下仅为一般性指标。
| Ratio | Favourable Change | Notes |
|---|---|---|
| Gross Margin | Increase | Higher sales or lower cost of sales |
| Net Margin | Increase | Better expense control |
| ROCE | Increase | More return per £1 employed |
| Current Ratio | Stable near 1.5-2 | Not too high, not too low |
| Quick Ratio | Stable near 1:1 | Excludes slow-moving inventory |
| Rec. Turnover Days | Decrease | Faster collection |
| Pay. Turnover Days | Increase (caution) | Better cash flow, but watch reputation |
| Inventory Turnover | Increase | Faster stock sold, less obsolescence |
Use these interpretations alongside common sense and specific business context when writing exam answers.
在答题时，请把这些解读与常识及具体商业情境结合起来使用。
Published by TutorHao | Accounting Revision Series | aleveler.com
更多咨询请联系16621398022（同微信）
或截图后用「扫一扫 → 相册」选择本图