📚 Year 12 WJEC Accounting: Formulas & Theorems Quick Reference Handbook | Year 12 WJEC 会计：公式定理速查手册
This handbook provides a concise yet comprehensive compilation of essential formulas and theorems required for Year 12 WJEC Accounting. It serves as a quick revision tool to help students master the numerical and conceptual foundations critical for exam success. Every formula is presented with its practical context, ensuring you can apply it accurately to financial statements, ratios and control procedures.
本手册简洁而全面地汇编了 Year 12 WJEC 会计所需的基本公式与定理，作为快速复习工具，帮助学生掌握对考试成功至关重要的计算与概念基础。每个公式都配有实务背景，确保你能在财务报表、比率分析和控制程序中准确运用。
1. The Accounting Equation and Double-Entry | 基本会计等式与复式记账
The accounting equation is the cornerstone of all financial record-keeping. It states that a business’s total resources are always funded by either external claims or the owner’s investment. This relationship must hold after every transaction.
会计等式是所有财务记录的基石。它表明企业的全部资源要么由外部索偿权融资，要么由所有者投入支撑。每笔交易发生后，这个关系必须始终保持成立。
Assets = Liabilities + Equity
资产 = 负债 + 所有者权益
Double-entry bookkeeping reflects this equality: every transaction has a debit and a credit of equal amount. The rules for debit and credit depend on the nature of the account.
复式记账正是这一平衡的体现：每笔交易均以相等金额的借方与贷方记录。借方与贷方的记账方向取决于账户性质。
- Assets: increase on debit, decrease on credit. / 资产：增加记借方，减少记贷方。
- Liabilities: increase on credit, decrease on debit. / 负债：增加记贷方，减少记借方。
- Equity (Capital): increase on credit, decrease on debit. / 所有者权益（资本）：增加记贷方，减少记借方。
- Income: increase on credit, decrease on debit. / 收入：增加记贷方，减少记借方。
- Expenses: increase on debit, decrease on credit. / 费用：增加记借方，减少记贷方。
If the equation ever appears unbalanced in the trial balance, an error has occurred—such as a one-sided entry or arithmetical mistake—and a suspense account may be needed temporarily.
如果在试算平衡表中等式无法平衡，就表明存在错误——例如单边入账或计算错误——此时可能需要临时开设暂记账户。
2. Gross Profit and Cost of Goods Sold | 毛利与销售成本
Gross profit is the surplus generated from buying and selling goods before deducting operating expenses. It is a key indicator of trading efficiency and pricing strategy.
毛利是在扣除营业费用之前，由商品买卖产生的盈余，是衡量交易效率和定价策略的关键指标。
Cost of Goods Sold (COGS) = Opening Inventory + Purchases − Closing Inventory
销售成本 = 期初存货 + 购货 − 期末存货
Gross Profit = Sales Revenue − Cost of Goods Sold
毛利 = 销售收入 − 销售成本
Purchases should be net of returns outwards (purchase returns), while sales revenue is shown after sales returns (returns inwards). Carriage inwards is added to the cost of purchases, because it is part of the cost of getting inventory ready for sale. Carriage outwards is treated as a selling expense and deducted later in the income statement.
购货应扣除购货退出（退货），销售收入应剔除销货退回。购货运费应计入购货成本，因为它是使存货达到可售状态的一部分；而销货运费则作为销售费用，在利润表后续部分扣除。
3. Net Profit and Expense Recognition | 净利与费用确认
Net profit (or net loss) reflects the overall profitability after accounting for all operating and non-operating items. It is calculated by deducting all expenses from gross profit and adding any other income.
净利润（或净亏损）反映了扣除所有经营与非经营项目后的整体盈亏，通过从毛利中扣除所有费用并加回其他收入得出。
Net Profit = Gross Profit + Other Income − Total Expenses
净利润 = 毛利 + 其他收入 − 总费用
The matching principle (accruals concept) requires that expenses are recognised in the period they are incurred, not necessarily when they are paid. Similarly, income is recorded when earned, regardless of cash receipt. This gives rise to adjustments for accruals and prepayments, as well as depreciation and bad debt provisions, all of which ensure the income statement reflects the true financial performance.
配比原则（应计概念）要求费用在发生的期间确认，而不论实际付款时间；同样，收入在赚取时记录，而不论现金收到时间。这就需要对应计与预付、折旧以及坏账准备进行调整，这些调整保证了利润表能如实反映真实的财务业绩。
4. Depreciation Methods: Straight-Line and Reducing Balance | 折旧方法：直线法与余额递减法
Depreciation systematically allocates the cost of a non-current asset over its useful life. The choice of method affects annual expense and net book value. Under WJEC, two main methods are examined.
折旧是将非流动资产成本在其使用寿命内系统分摊的过程。方法的选用会影响每年的费用和账面净值。在 WJEC 考试中，主要考查两种方法。
Straight-line method: Equal amount of depreciation each year, based on original cost less residual value. This method is simple and suitable for assets that provide steady benefit over time.
直线法：每年计提相等的折旧额，以原始成本减去残值为基础。该方法简单，适用于提供稳定效益的资产。
Annual Depreciation = (Cost − Residual Value) ÷ Useful Life (years)
年折旧额 =（成本 − 残值）÷ 有用年限
Reducing balance method: A fixed percentage is applied to the net book value (cost less accumulated depreciation) each year. This results in higher depreciation in early years and lower charges later, matching assets that lose value more quickly initially.
余额递减法：每年按固定百分比乘以账面净值（成本减累计折旧）计算。这样早期折旧多，后期少，符合初期贬值较快的资产特征。
Annual Depreciation = Net Book Value × Depreciation Rate (%)
年折旧额 = 账面净值 × 折旧率（%）
When an asset is sold, the profit or loss on disposal is the difference between the sale proceeds and the net book value at disposal date. The asset account and accumulated depreciation are eliminated, and the profit or loss is transferred to the income statement.
资产出售时，处置利得或损失即为售价与处置日账面净值之差。此时需注销资产账户和累计折旧，并将处置损益结转至利润表。
5. Bad Debts and Provision for Doubtful Debts | 坏账与呆账准备
Bad debts are trade receivables that are confirmed irrecoverable. They are written off as an expense in the income statement. A provision for doubtful debts, however, is an estimate of future losses, created under the prudence concept.
坏账是已确认无法收回的应收账款，作为费用在利润表中注销。而呆账准备则是对未来损失的估计，依据审慎概念计提。
Writing off a bad debt: Debit Bad Debts Expense, Credit Trade Receivables. It reduces both profit and the receivables balance.
坏账注销：借记坏账费用，贷记应收账款。既减少利润，也减少应收款余额。
Provision for doubtful debts: The required provision is usually calculated as a percentage of trade receivables at year-end. The income statement is charged only with the increase in provision; a decrease in provision is treated as income.
呆账准备：通常按期末应收账款的一定百分比计算所需准备。利润表仅计入准备的增加额；若减少，则作为收益处理。
Increase in Provision = Required Provision at Year End − Opening Provision
准备增加额 = 期末所需准备 − 期初准备
If the required provision falls, the reduction is credited to the income statement, increasing profit. In the statement of financial position, trade receivables are shown net of the total provision for doubtful debts.
如果所需准备减少，差额将贷记利润表、增加利润。在财务状况表中，应收账款按扣除呆账准备总额后的净额列示。
6. Accruals and Prepayments in Financial Statements | 应计与预付的财务报表调整
Accruals and prepayments ensure that expenses and income are recorded in the correct accounting period. An accrual is an amount owing for an expense already consumed or for income earned but not yet received. A prepayment is an amount paid in advance for a benefit not yet received.
应计与预付保证费用和收入被记录在正确的会计期间。应计是指已经发生但尚未支付的费用，或已赚得但尚未收到的收入。预付是指提前支付但尚未享受利益的款项。
For expenses, the formula to determine the charge to the income statement is:
费用在利润表中的计算金额公式为：
Expense per Income Statement = Amount Paid + Closing Accrual − Opening Accrual or − Closing Prepayment + Opening Prepayment
利润表费用 = 已付金额 + 期末应计 − 期初应计 或 − 期末预付 + 期初预付
For example, electricity paid during the year was £4,500, with an opening accrual of £200 and a closing accrual of £320. The expense charged to the income statement is £4,500 + £320 − £200 = £4,620. A similar adjustment applies to income: tax receivable, commission receivable, or rent receivable may need accrued income or income received in advance (deferred income) recognised.
例如，年内电费付款 £4,500，期初应计 £200，期末应计 £320，则计入利润表的电费应为 £4,500 + £320 − £200 = £4,620。收入的调整类似：应计税收益、佣金收入或租金收入可能需要确认应计收入或预收收入（递延收入）。
7. Inventory Valuation: FIFO and AVCO | 存货计价：先进先出与加权平均成本法
Under IAS 2, inventories must be valued at the lower of cost and net realisable value. When identical items are purchased at different prices, cost must be determined using a cost flow assumption. WJEC requires candidates to apply FIFO and AVCO.
根据 IAS 2，存货必须按成本与可变现净值孰低计量。当相同物品以不同价格购得时，需采用成本流动假设来确定成本。WJEC 要求考生掌握先进先出法和加权平均成本法。
FIFO (First In, First Out): The earliest purchased items are assumed to be sold first. Closing inventory consists of the most recent purchases, so its value rises with increasing prices. During inflation, FIFO produces a higher closing inventory value and a lower COGS, leading to higher reported profit.
FIFO（先进先出法）：假设最早购入的存货最先发出。期末存货由最近的购货构成，因此价格上升时存货价值较高。通胀下，FIFO 带来较高期末存货价值和较低销售成本，导致账面利润较高。
AVCO (Weighted Average Cost): A new average cost per unit is recalculated after each purchase (continuous weighted average) or at the end of the period. The average cost is used to value both cost of sales and closing inventory, smoothing out price fluctuations.
AVCO（加权平均成本法）：每次购货后（连续加权平均）或期末一次性计算新的单位平均成本。该平均成本用于计算销售成本和期末存货，从而平滑价格波动。
Weighted Average Cost per Unit = Total Cost of Inventory Available ÷ Total Units Available
加权平均单位成本 = 可供销售的存货总成本 ÷ 可供销售的总数量
Regardless of the method, if net realisable value (estimated selling price less costs to completion and sale) falls below cost, inventory must be written down, recognising a loss and ensuring assets are not overstated.
无论采用何种方法，如果可变现净值（估计售价减至完工及销售费用）低于成本，则存货必须计提跌价准备，确认损失，确保资产不被高估。
8. Ratio Analysis: Profitability and Efficiency | 比率分析：盈利能力与效率
Financial ratios allow stakeholders to interpret relationships within the financial statements. Profitability ratios assess the ability to generate earnings, while efficiency ratios evaluate how well resources are managed. The following are core WJEC formulas.
财务比率帮助利益相关者解读财务报表内部的关系。盈利比率评估创造利润的能力，效率比率则评价资源管理的水平。以下是 WJEC 的核心计算公式。
| Ratio / 比率 | Formula / 公式 | Purpose / 目的 |
|---|---|---|
| Gross Profit Margin / 毛利率 | (Gross Profit ÷ Revenue) × 100% | Measures trading profitability before overheads. / 衡量扣除间接费用前的交易盈利性。 |
| Net Profit Margin / 净利润率 | (Net Profit Before Interest and Tax ÷ Revenue) × 100% | Indicates overall profitability after all operating expenses. / 反映所有营业费用后的整体盈利能力。 |
| Return on Capital Employed (ROCE) / 已用资本回报率 | (Profit Before Interest and Tax ÷ Capital Employed) × 100% Capital Employed = Equity + Non-current Liabilities (or Total Assets − Current Liabilities) |
Shows return on funds invested by shareholders and lenders. / 反映股东和贷方投入资金的回报水平。 |
| Inventory Turnover / 存货周转率 | Cost of Sales ÷ Average Inventory Average Inventory = (Opening + Closing Inventory) ÷ 2 |
How many times inventory is sold and replaced. High turnover suggests efficient stock management. / 存货一年中销售和重置的次数。高周转率意味着库存管理高效。 |
| Trade Receivables Days / 应收账款周转天数 | (Trade Receivables ÷ Credit Sales) × 365 | Average time taken to collect debts. Lower days improve cash flow. / 平均收款时长。天数越少，现金流越佳。 |
| Trade Payables Days / 应付账款周转天数 | (Trade Payables ÷ Credit Purchases) × 365 | Average period taken to pay suppliers. Higher days may indicate reliance on trade credit. / 平均付款时长。天数越高，可能表明对商业信用的依赖越大。 |
When interpreting ratios, always consider industry averages, trends over time and the underlying accounting policies. A single ratio in isolation rarely tells the full story.
解读比率时，始终要考虑行业平均值、时间趋势和基本会计政策。孤立地看单一比率很少能揭示全貌。
9. Ratio Analysis: Liquidity and Gearing | 比率分析：流动性与杠杆
Liquidity ratios measure a firm’s ability to meet short-term obligations, while gearing assesses long-term financial structure and risk. These are essential for going-concern evaluation and by lenders.
流动性比率衡量企业履行短期义务的能力，杠杆比率则评价长期财务结构和风险水平。它们对持续经营评估以及贷款方都至关重要。
| Ratio / 比率 | Formula / 公式 | Note / 说明 |
|---|---|---|
| Current Ratio / 流动比率 | Current Assets ÷ Current Liabilities | A ratio >1 suggests sufficient cover; excessive levels may indicate idle assets. / 比率>1表明足够覆盖；过高可能意味着资产闲置。 |
| Quick Ratio (Acid Test) / 速动比率（酸性测试） | (Current Assets − Inventory) ÷ Current Liabilities | Excludes inventory, the least liquid current asset. Ideal often 1:1, but varies. / 排除流动性最差的存货。理想常为 1:1，但视行业而定。 |
| Gearing Ratio / 杠杆比率 | (Non-current liabilities ÷ Capital Employed) × 100% or (Debt ÷ (Debt + Equity)) × 100% |
High gearing indicates greater reliance on borrowing and higher financial risk. / 高杠杆表明更多依赖借款，财务风险更大。 |
For liquidity, it is also important to check the cash and cash equivalents, as well as the quality of trade receivables. For gearing, compare with similar firms, as capital-intensive industries normally carry higher debt.
针对流动性，还需关注现金及现金等价物以及应收账款的质量。就杠杆而言，应与同类公司比较，因为资本密集型行业通常负债较高。
10. Partnership Appropriation and Accounts | 合伙企业利润分配与账户
In a partnership, profit is appropriated according to the partnership agreement, which may include interest on capital, partners’ salaries, and interest on drawings before sharing residual profit. The appropriation must be clearly shown in the partnership accounts.
在合伙企业中，利润根据合伙协议进行分配，分配时可包含资本利息、合伙薪金和提款利息，然后再分配剩余利润。这些分配必须在合伙账目中得到清晰呈现。
Key formulas and rules:
关键公式与规则：
- Interest on Capital: Applied to the opening balance of the capital account (or fixed capital). Formula: Capital balance × Interest rate (%).
- 资本利息：按资本账户期初余额（或固定资本）计算。公式：资本余额 × 利率（%）。
- Partners’ Salaries: A fixed amount agreed for partners who perform active duties. It is treated as an appropriation, not an expense.
- 合伙薪金：为履行积极职责的合伙人约定的固定金额，作为利润分配而非费用。
- Interest on Drawings: Charged on partners’ withdrawals to discourage excessive drawings. It increases the profit available for sharing.
- 提款利息：对合伙人提款收取，以抑制过度提款，并增加可用于分配的利润。
- Residual Profit Share: After the above allocations, the remaining profit (or loss) is divided according to the agreed profit-sharing ratio (PSR).
- 剩余利润分享：完成上述分配后，
Published by TutorHao | Year 12 Accounting Revision Series | aleveler.com
更多咨询请联系16621398022（同微信）
屏轩国际教育cambridge primary/secondary checkpoint, cat4, ukiset,ukcat,igcse,alevel,PAT,STEP,MAT, ibdp,ap,ssat,sat,sat2课程辅导，国外大学本科硕士研究生博士课程论文辅导