The Ultimate CPA Guide to Cost Accounting & Variance Analysis
The Ultimate CPA Guide to Cost Accounting & Variance Analysis
BAR exam review: product costs, cost flows, overhead, spoilage, ABC, absorption vs. variable costing, and all eight variances
Cost accounting and variance analysis are some of the most calculation-heavy topics on BAR — and some of the easiest places to lose points if you confuse standard with actual, or memorize formulas without understanding the structure underneath them.
This guide builds from the ground up: product costs vs. period costs, how costs move through inventory, how overhead is allocated, how spoilage works, how absorption and variable costing differ, how activity-based costing works, and finally the full framework for all eight variances with worked examples.
Who this guide is for:
- BAR students who need a full cost accounting and variance review
- Students who want a clean framework for all eight variances
- Anyone struggling with inventory cost flows, overhead allocation, or spoilage
- Students looking for a final formula-reference style review before exam day
Jump to:
- How BAR Tests Cost Accounting
- Product vs. Period Costs
- Flow of Costs
- Manufacturing Overhead
- Spoilage
- Absorption vs. Variable Costing
- Activity-Based Costing
- Variance Analysis Intro
- Direct Materials Variances
- Direct Labor Variances
- Variable Overhead Variances
- Fixed Overhead Variances
- All Eight Variances
- Quick Reference Glossary
- FAQ
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Get My Free CPA 101 CourseHow Does the BAR Exam Test Cost Accounting? BAR
Cost and managerial accounting sits inside Area I: Business Analysis. It is tested across multiple skill levels, from basic classification questions to multi-step variance analysis.
| Representative Task | Skill Level |
|---|---|
| Calculate fixed, variable, and mixed costs | Application |
| Describe and use absorption, variable, activity-based, process, and job order costing | Application |
| Derive the appropriate variance analysis method by analyzing business scenarios | Analysis |
| Interpret results through price, volume, and mix analysis | Analysis |
What this means for your exam prep
- Cost classifications and costing methods are tested at the application level
- Variance analysis is tested at the analysis level
- The blueprint specifically names absorption, variable, activity-based, process, and job order costing
Product Costs vs. Period Costs BAR
One of the first decisions in cost accounting is classification. The exam often tests whether a cost should stay on the balance sheet in inventory or go straight to the income statement.
Product Costs High-Yield
Product costs are tied to creating a product. They accumulate in inventory and move to Cost of Goods Sold only when the product is sold.
| Component | Example (Laptop Manufacturer) |
|---|---|
| Direct Materials | Glass, aluminum — directly traceable to each unit |
| Direct Labor | Assembly workers' wages — directly traceable to each unit |
| Manufacturing Overhead | Factory rent, utilities, floor manager salary — indirect and not traceable to a single unit |
Study Tip: Product costs are expensed when the units are sold, not when they are manufactured.
Period Costs
Period costs are not associated with manufacturing. They are expensed immediately in the period incurred.
Examples include marketing salaries, accountant salaries, and legal fees. These costs normally appear below gross profit as G&A or operating expenses.
Study Tip: Period costs hit the income statement right away. Product costs are deferred until sale.
Income Statement Format
− Cost of Goods Sold (product costs for units sold)
= Gross Profit
− General & Administrative Expenses (period costs)
= Net Income
Example: Platinum Tech Laptop Manufacturer
Platinum Tech spends $1,000,000 producing 1,000 laptops, or $1,000 per unit, but sells only 200 at $2,000 each.
Only the 200 laptops sold become expense: COGS = 200 × $1,000 = $200,000. The remaining $800,000 stays in Finished Goods Inventory.
| Account | Debit | Credit |
|---|---|---|
| Cost of Goods Sold | $200,000 | |
| Finished Goods Inventory | $800,000 | |
| Cash / Accounts Payable | $1,000,000 |
With a $50,000 marketing manager salary added as a period cost: Revenue $400,000 − COGS $200,000 = Gross Profit $200,000 − G&A $50,000 = Net Income $150,000.
Prime Costs and Conversion Costs
| Term | Components | Note |
|---|---|---|
| Prime Costs | Direct Materials + Direct Labor | The most direct inputs to the product |
| Conversion Costs | Direct Labor + Manufacturing Overhead | Costs to convert raw materials into finished goods |
Direct labor appears in both groups — it is the overlap between prime costs and conversion costs.
Common Trap: Students often expense all manufacturing spending immediately. That is wrong. Only the cost attached to units actually sold becomes expense this period.
Flow of Costs: The Three Inventory Accounts BAR
| Account | What It Holds | When Costs Move Out |
|---|---|---|
| Raw Materials Inventory | Materials purchased but not yet used in production | When materials are issued to production |
| Work-in-Process (WIP) | DM + DL + MOH for partially completed units | When units are completed |
| Finished Goods Inventory | Completed units not yet sold | When units are sold and become COGS |
Flow of Costs Example: Platinum Tech
Platinum Tech purchases $200,000 of raw materials and records them in Raw Materials Inventory.
Production begins on 400 laptops using $140,000 of raw materials, $16,000 of direct labor, and $8,000 of applied overhead. Total cost moved into WIP is $164,000.
All 400 laptops are completed, so the full $164,000 moves to Finished Goods, or $410 per unit.
If 100 laptops are sold, then 100 × $410 = $41,000 moves from Finished Goods to COGS.
Kyle’s 90+ Score Insight: The most common mistake here is expensing all production costs immediately. Only the cost of units actually sold reaches the income statement. Everything else stays on the balance sheet in inventory.
Manufacturing Overhead Allocation BAR
Overhead is difficult because it is indirect, uncertain at the beginning of the period, and tied to uncertain production volume. That is why companies estimate a rate in advance.
Overhead Allocation Example
Expected overhead is $10,000. Expected production is 500 units × 2 direct labor hours each = 1,000 estimated DL hours.
At period end, only 760 actual DL hours were used, so applied overhead is 760 × $10 = $7,600. Actual overhead incurred is $11,000.
Under-applied overhead = $11,000 − $7,600 = $3,400. That amount is debited to COGS.
| Situation | Meaning | Adjustment to COGS |
|---|---|---|
| Under-Applied | Actual overhead > applied overhead | Debit COGS |
| Over-Applied | Actual overhead < applied overhead | Credit COGS |
Study Tip: Under-applied overhead increases COGS. Over-applied overhead decreases COGS.
Spoilage: Normal vs. Abnormal BAR
| Type | Definition | Accounting Treatment | Example |
|---|---|---|---|
| Normal Spoilage | Occurs in the ordinary course of business | Treated as a product cost | Dropping pizzas; minor normal defects |
| Abnormal Spoilage | Outside normal operations | Expensed immediately as a period cost | Factory fire; storm damage |
Spoilage Example: New York Pizza Company
The company makes 1,000 pizzas. During production, dropped pizzas create $150 of normal spoilage. A lightning storm ruins ingredients, creating $700 of abnormal spoilage.
| Cost Item | Amount | Classification |
|---|---|---|
| Direct Materials | $2,000 | Product cost |
| Direct Labor | $1,000 | Product cost |
| Manufacturing Overhead | $500 | Product cost |
| Normal Spoilage | $150 | Product cost |
| G&A Expenses | $400 | Period cost |
| Abnormal Spoilage | $700 | Period cost |
Per-unit inventory cost: ($2,000 + $1,000 + $500 + $150) / 1,000 = $3.65 per pizza
Total period costs: $400 + $700 = $1,100
Common Trap: Students often treat all spoilage the same way. Normal spoilage stays with product cost. Abnormal spoilage is expensed immediately.
Variance analysis is where BAR candidates most often leave points on the table.
My Free CPA 101 Course walks through the exact framework I used to keep all eight variances straight on exam day. Check it out here.
Absorption Costing vs. Variable Costing BAR
| Absorption Costing (GAAP) | Variable Costing (Internal) | |
|---|---|---|
| Also Called | Traditional method; full costing | Contribution method |
| Fixed Overhead | Product cost | Period cost |
| Income Statement | Sales − COGS = Gross Profit − G&A = Operating Income | Sales − Variable Costs = Contribution Margin − Fixed Costs = Operating Income |
| Required For | External financial reporting | Internal decision-making |
When do the two methods show different income?
| Scenario | Higher Income Under | Why |
|---|---|---|
| Produced > Sold | Absorption costing | Some fixed OH stays in ending inventory |
| Produced < Sold | Variable costing | Absorption pulls prior fixed OH out of inventory and into COGS |
| Produced = Sold | Same under both | No inventory build-up or draw-down |
Study Tip: Fixed overhead is the only difference. When production exceeds sales, absorption costing usually shows higher income.
Activity-Based Costing (ABC) BAR
Why traditional cost accounting can fall short
1. A single driver can miss important pre-production costs. If setup, testing, or calibration matter, a simple machine-hour allocation may ignore real cost drivers.
2. Traditional accounting cannot tie many support costs to specific products. Customer complaints, support calls, or distribution demands may differ dramatically by product, but traditional accounting may bury those costs in period expenses.
Two major differences from the traditional method
- ABC does not rely on the traditional product-cost vs. period-cost distinction for internal analysis
- ABC uses multiple cost pools and drivers instead of a single company-wide allocation base
The three steps of ABC
Allocate total costs into cost pools
Identify activities like production, packaging, shipping, advertising, or customer support and estimate the total cost of each.
Choose a cost driver for each pool
Machine hours, shipments, complaint calls, or setups may each serve as the best driver depending on the activity.
Compute each pool’s allocation rate
Cost pool ÷ cost driver = rate. Then assign cost to products based on actual driver usage.
Study Tip: ABC is for internal use only. Traditional absorption costing is still required for GAAP external reporting.
Introduction to Variance Analysis BAR High-Yield
Variance analysis answers two big questions: did we pay more or less per unit of input than expected, and did we use more or fewer inputs than expected?
The Eight Variances
| Cost Component | Variance 1 | Variance 2 |
|---|---|---|
| Direct Materials | Price Variance | Efficiency Variance |
| Direct Labor | Price Variance | Efficiency Variance |
| Variable Overhead | Price Variance | Efficiency Variance |
| Fixed Overhead | Spending Variance | Production Volume Variance |
Four rules that apply to every variance
- Standard means estimated
- Expected units produced is irrelevant for the first three categories — actual output matters
- Favorable = actual better than standard; unfavorable = actual worse than standard
- Price = rate and efficiency = usage depending on textbook wording
Kyle’s 90+ Score Insight: For price/rate variances, multiply by actual quantity. For efficiency/usage variances, multiply by standard price or rate. That one structural rule keeps the first six variances straight.
Direct Materials Variance Analysis BAR High-Yield
Price Variance
Multiplied by actual quantity. Favorable if actual price is lower than standard.
Efficiency Variance
Multiplied by standard price. Favorable if fewer materials were used than expected.
Worked Example: Home Manufacturer
| Standard | Actual | |
|---|---|---|
| Homes produced | 50 (irrelevant) | 35 |
| Board feet of wood per home | 6,000 | 6,500 |
| Cost per board foot | $2.00 | $1.75 |
Price Variance: ($1.75 − $2.00) × 6,500 × 35 = $56,875 Favorable
Efficiency Variance: (6,500 − 6,000) × $2.00 × 35 = $35,000 Unfavorable
Direct Labor Variance Analysis BAR High-Yield
Price Variance
Multiplied by actual hours. Unfavorable if the hourly wage was higher than expected.
Efficiency Variance
Multiplied by standard rate. Favorable if fewer hours were used than expected.
Worked Example: Home Manufacturer
| Standard | Actual | |
|---|---|---|
| Homes produced | 50 (irrelevant) | 35 |
| Labor hours per home | 400 | 375 |
| Cost per labor hour | $20.00 | $21.00 |
Price Variance: ($21 − $20) × 375 × 35 = $13,125 Unfavorable
Efficiency Variance: (375 − 400) × $20 × 35 = $17,500 Favorable
Variable Overhead Variance Analysis BAR
Price Variance
Example: ($2.00 − $1.50) × 5 × 100 = $250 Unfavorable
Efficiency Variance
Example: (5 − 4) × $1.50 × 100 = $150 Unfavorable
Fixed Overhead Variance Analysis BAR High-Yield
Fixed Overhead Allocation Rate
Because fixed overhead does not change with volume, the company sets a per-unit rate at the start of the period and applies it to units produced throughout the year.
Spending Variance
Measures whether total fixed OH spend was more or less than expected.
Production Volume Variance
Measures whether fewer or more units were produced than planned.
Worked Example: Frame Manufacturer
| Budgeted | Actual | |
|---|---|---|
| Frames produced | 20,000 | 19,000 |
| Fixed overhead costs | $20,000 | $22,000 |
| Allocation rate | $1.00 per unit | — |
Spending Variance: $20,000 − $22,000 = $2,000 Unfavorable
Production Volume Variance: (20,000 − 19,000) × $1.00 = $1,000 Unfavorable
Kyle’s 90+ Score Insight: Producing fewer units creates an unfavorable production volume variance because fixed costs do not shrink with output. You allocated overhead based on a higher expected production level, but actual production absorbed less overhead than planned.
All Eight Variances: Formula Reference
Use this as a final study reference. The first six follow the same structure. Fixed overhead is the exception.
| Variance | Formula | Key Multiplier |
|---|---|---|
| Direct Materials | ||
| Price Variance | (Actual Price − Standard Price) × Actual Qty/Unit × Units Produced | Actual Qty |
| Efficiency Variance | (Actual Qty/Unit − Standard Qty/Unit) × Standard Price × Units Produced | Standard Price |
| Direct Labor | ||
| Price Variance | (Actual Rate − Standard Rate) × Actual Hours/Unit × Units Produced | Actual Hours |
| Efficiency Variance | (Actual Hours/Unit − Standard Hours/Unit) × Standard Rate × Units Produced | Standard Rate |
| Variable Overhead | ||
| Price Variance | (Actual OH/Driver − Standard OH/Driver) × Actual Drivers/Unit × Units Produced | Actual Drivers |
| Efficiency Variance | (Actual Drivers/Unit − Standard Drivers/Unit) × Standard Rate × Units Produced | Standard Rate |
| Fixed Overhead | ||
| Spending Variance | Standard Total Fixed OH − Actual Total Fixed OH | Total $ |
| Production Volume Variance | (Standard Units − Actual Units) × Allocation Rate | Unit Difference |
Quick Reference Glossary
| Term | One-Line Definition |
|---|---|
| Product Costs | DM + DL + MOH; stay in inventory until sold |
| Period Costs | Non-manufacturing costs expensed immediately |
| Prime Costs | Direct Materials + Direct Labor |
| Conversion Costs | Direct Labor + Manufacturing Overhead |
| Raw Materials Inventory | Materials purchased but not yet used |
| Work-in-Process | Units in production with DM + DL + MOH attached |
| Finished Goods | Completed units not yet sold |
| Under-Applied Overhead | Actual OH > applied OH; debit COGS |
| Over-Applied Overhead | Actual OH < applied OH; credit COGS |
| Normal Spoilage | Expected spoilage; treated as product cost |
| Abnormal Spoilage | Unexpected spoilage; expensed immediately |
| Absorption Costing | GAAP method; fixed OH is a product cost |
| Variable Costing | Internal method; fixed OH is a period cost |
| Contribution Margin | Sales − variable costs |
| Activity-Based Costing | Internal costing method using multiple cost pools and drivers |
| Standard | The estimated amount used in variance analysis |
| Favorable Variance | Actual result is better than standard |
| Unfavorable Variance | Actual result is worse than standard |
| Price / Rate Variance | Measures input cost vs. standard; uses actual quantity |
| Efficiency / Usage Variance | Measures input usage vs. standard; uses standard price |
| Fixed OH Spending Variance | Budgeted fixed OH vs. actual fixed OH |
| Fixed OH Production Volume Variance | Volume difference × fixed OH allocation rate |
FAQ
What is the difference between product costs and period costs?
Product costs are DM, DL, and MOH and stay in inventory until sale. Period costs are expensed immediately.
What is the most important variance rule to memorize?
For the first six variances, price/rate variances use actual quantity, while efficiency/usage variances use standard price or rate.
How do absorption and variable costing differ?
The only difference is fixed overhead. Absorption treats it as a product cost. Variable costing treats it as a period cost.
How is normal spoilage treated?
Normal spoilage is treated as a product cost and flows through inventory. Abnormal spoilage is expensed immediately.
Is activity-based costing allowed under GAAP for external reporting?
No. ABC is used for internal decision-making. Traditional absorption costing is required for external GAAP financial statements.
Ready to master the full BAR exam?
Cost accounting and variance analysis are just one piece of BAR. My Free CPA 101 Course gives you a complete roadmap for studying smarter across all four sections — including the strategies that helped me score 90+ on every section.
Kyle Ashcraft is a CPA who scored a 90+ on all four CPA exams. Kyle founded Maxwell CPA Review, which is an exam-prep company that offers a comprehensive CPA exam review course and private tutoring.