Calculate activity driver rates
Divide each activity pool by its total driver units and label the rate so it can be applied consistently.
Section 4.1 · Activity based costing
Exam scope and assessment notes
Cambridge International AS & A Level Accounting 9706, 2026–2028 syllabus, Version 2. Topic 4.1 covers activity-based costing (ABC), cost drivers, overhead apportionment and allocation, unit cost and selling-price calculations, method comparisons, uses and limitations, and supported decisions. Practice is self-checked, not an official Cambridge grade. Full timed Papers 1–4 and human subject-teacher review remain outstanding.
Before you begin
- Use AS Topic 2.1–2.2 knowledge of fixed and variable costs, overhead absorption, cost-plus pricing and contribution. This A Level pathway compares those methods with activity-based costing.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
What should you check before calculating an activity rate?
What you will learn
- Calculate rates for multiple activity pools
- Keep driver units aligned with their pools
- Check rates using total activity
Calculate one rate for each pool
Activity driver rate = activity cost pool ÷ total driver units. For example, a $120,000 set-up pool with 600 set-ups gives $200 per set-up. A $180,000 machine pool with 90,000 machine hours gives $2 per machine hour.
Every rate must retain its driver unit. Do not divide set-up costs by machine hours or mix total units with batch counts. When all products' activity counts are multiplied by the rate, the allocations should reconcile to the cost pool, subject to rounding.
Check the rate before allocation
Use the activity total for the same period as the pool. If the denominator omits some product or includes unrelated activity, the rate will be distorted. Check dates, units and whether the stated rate is based on actual or budgeted activity.
A rate is an allocation mechanism, not necessarily the marginal cost of one extra activity. Some pool costs are fixed for the period; changing one driver's use may not immediately change total overhead cash spending.
Pause and explain
Why does 240 × $200 = $48,000 help check a rate?
Worked example
A $48,000 inspection pool has 240 inspections. Calculate the driver rate and check the cost allocated if all 240 inspections are assigned.
Show the worked solution
- $48,000 ÷ 240 = $200 per inspection.
- 240 × $200 = $48,000.
- The check returns the full pool total.
Answer The rate is $200 per inspection and allocating all inspections assigns $48,000.
Try a topic test
Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.
Test this topic →From guided practice to a new situation
Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
A set-up pool is $120,000 for 600 set-ups. Calculate the rate and the allocation for Product A using 120 set-ups.
Give me a hint
Find the rate first; then multiply by A's activity.
Compare my reasoning
- Rate = $120,000 ÷ 600 = $200 per set-up.
- A allocation = 120 × $200 = $24,000.
- Keep the rate labelled per set-up and the allocation as total dollars.
The rate is $200 per set-up; Product A receives $24,000.
Look for these in your work
- Calculate $200 per set-up.
- Multiply by 120 set-ups.
- Report the $24,000 pool allocation.
A machine-processing pool is $180,000 for 90,000 hours. Product X uses 2,000 hours. Calculate the rate and X's overhead allocation.
Give me a hint
Divide by total machine hours, then apply X's hours.
Compare my reasoning
- Rate = $180,000 ÷ 90,000 = $2 per machine hour.
- X allocation = 2,000 × $2 = $4,000.
- Check that the driver units are machine hours for both rate and product usage.
The rate is $2 per machine hour and X receives $4,000.
Look for these in your work
- Use machine hours as the driver.
- Calculate the $2 rate.
- Allocate $4,000 to X.
A budgeted activity pool is $100,000 for 2,000 orders, but actual activity is 2,500 orders. The question asks for a budgeted ABC rate. What rate should be used and what should be stated?
Give me a hint
Use the denominator and basis named by the question; explain that actual activity differs.
Compare my reasoning
- Budgeted rate = $100,000 ÷ 2,000 = $50 per order.
- Applying that budgeted rate to 2,500 actual orders would allocate $125,000 before any variance analysis.
- State that the rate is budgeted and reconcile the over/under-absorption rather than silently replacing it with an actual rate.
Use $50 per order for a budgeted-rate calculation and explain that applying it to actual activity allocates $125,000, requiring variance analysis.
Look for these in your work
- Use budgeted pool and activity totals.
- Calculate the $50 rate.
- Identify the $25,000 difference when applied to actual volume.
Common mistakes
- Dropping the per-driver unit from the answer
- Using activity volume from the wrong period
- Calling the rate a variable cash cost without evidence
What can you explain now?
A $75,000 pool has 1,500 driver units. What is the rate?
Compare with the explanation
$50 per driver unit
Divide pool cost by driver units and label the result per driver unit.
After trying it yourself, choose your next review. This is your self-assessment.
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Make it stick
Write the activity-rate formula and two checks to make before using it.
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.