Fundamentals of Financial and Cost Accounting · Cost, Cost Centre, Cost Unit and Cost Drivers

Cost Drivers: Meaning, Types and Examples

Updated 10 October 2026 · Fact-checked

A cost driver is a factor that causes a cost to rise or fall. Volume-based drivers, such as machine hours or units produced, link cost to output. Activity-based drivers, such as number of set-ups or purchase orders, link cost to the activities performed. To solve a question, find the activity, then pick the driver that best explains its cost.

Understand Cost Drivers and Activity Based Concepts

A cost is the amount spent to make a product or give a service. A cost driver is the reason that cost goes up or down. If you know the driver, you know what to control.

Take a courier firm in Pune. Its fuel cost changes with kilometres driven. So kilometres driven is the cost driver of fuel. Its billing cost changes with the number of invoices raised. So number of invoices is the driver of billing cost.

There are two broad kinds. Volume-based drivers depend on how much you produce, such as units produced, direct labour hours or machine hours. Activity-based drivers depend on the work done to support production, such as number of set-ups, purchase orders, inspections, material movements or customer orders. These costs may not change with units at all.

In Activity Based Costing (ABC), overheads are first collected in cost pools for each activity. Each pool is then assigned to products using its cost driver. This gives a more accurate cost than spreading all overhead on one basis such as labour hours.

Do not confuse a cost driver with a cost object. A cost object is the thing you want to cost, such as a product, job or department. A cost driver is the cause of the cost. The driver is used to trace cost to the object.

Key formulas to remember

Cost driver rate: Cost driver rate = Total cost of the activity pool ÷ Total quantity of the cost driver; Used in ABC. For example, ₹ per set-up or ₹ per purchase order.
Overhead assigned to a cost object: Overhead assigned = Cost driver rate × Quantity of driver used by the cost object; Do this for each activity pool and add the results.
Overhead per unit: Overhead per unit = Total overhead assigned to the product ÷ Number of units produced; Use the units of that product only.

How to solve Cost Drivers and Activity Based Concepts questions

Use this method for any question on cost drivers, whether it asks for a definition, an example or a small calculation.

1Read the question and find what is being asked: meaning, matching, classification or a rate calculation.
2Identify the activity or cost in question, such as machine set-up, material handling or quality inspection.
3Ask what causes this cost to change. That cause is the cost driver.
4Decide whether the driver depends on output volume (volume-based) or on the work done (activity-based).
5For calculations, divide the activity cost pool by the total driver quantity to get the cost driver rate.
6Multiply the rate by the driver quantity used by each product or cost object.
7Add the amounts across activities and divide by units if cost per unit is asked.
8Check that the cost object is the thing being costed and the driver is the cause, not the same thing.

Quickest way: Match the cost to its cause

When to use it: Use this for matching and example-based MCQs where you must pick the right driver.

Underline the cost named in the question.
Ask: what makes this cost double if I double it? That is the driver.
Eliminate options that are cost objects, such as products or departments.
Eliminate options that are costs themselves, such as rent or wages.
For calculations, compute rate first, then multiply. Skip full cost sheets.

Common mistakes in Cost Drivers and Activity Based Concepts

Treating a cost driver and a cost object as the same.
Both terms are linked to cost and sound similar.
Fix: A cost object is what you cost (product, job). A cost driver is what causes the cost (set-ups, hours).
Assuming every driver is based on units produced.
Traditional costing uses volume for all overheads.
Fix: Remember that ABC uses activity drivers, such as number of orders, which can be unrelated to units.
Naming a cost as its own driver, such as 'rent' for rent.
Students confuse the item with its cause.
Fix: A driver is a measure of activity, such as floor area or number of inspections.
Dividing the pool cost by units instead of driver quantity.
Habit from the overhead absorption rate per unit.
Fix: The denominator is the total quantity of the driver for that activity.
Using one driver for all overheads in an ABC question.
Students rush and skip the activity pools.
Fix: Use a separate driver and rate for each activity pool given.

Worked examples

Example 1

A factory has set-up cost of ₹1,20,000 for the year. There were 60 set-ups in total. Product A needed 20 set-ups and Product B needed 40. Find the set-up cost assigned to each product.

Show the solution

Cost driver is the number of set-ups.
Cost driver rate = ₹1,20,000 ÷ 60 = ₹2,000 per set-up.
Product A = 20 × ₹2,000 = ₹40,000.
Product B = 40 × ₹2,000 = ₹80,000.
Check: ₹40,000 + ₹80,000 = ₹1,20,000.

Answer: Product A gets ₹40,000 and Product B gets ₹80,000 of set-up cost.

Example 2

Which of the following is an activity-based cost driver for the cost of purchasing department? (A) Units produced (B) Number of purchase orders (C) Direct labour hours (D) Machine hours

Show the solution

The purchasing department's work is placing orders.
Its cost changes with the number of orders handled.
Units produced, labour hours and machine hours are volume-based measures linked to output.
So the activity-based driver is the number of purchase orders.

Answer: (B) Number of purchase orders

Exam tips

Expect definition and matching MCQs: pick the cause of the cost, not the cost itself.
Learn a few standard pairs: set-ups with number of set-ups, inspection with number of inspections, material handling with number of movements.
For rate questions, always divide by the driver quantity, then check that the parts add up to the pool.
If an option is a product, job or department, it is a cost object, so eliminate it as a driver.

Practice questions from Cost, Cost Centre, Cost Unit and Cost Drivers

Cost Drivers and Activity Based Concepts in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Cost Drivers and Activity Based Concepts: frequently asked questions

What is a cost driver in cost accounting?

A cost driver is a factor that causes the cost of an activity to change. Examples are machine hours, number of set-ups and number of orders. Knowing the driver helps you trace and control cost.

What is the difference between a cost driver and a cost object?

A cost object is the item you want to find the cost of, such as a product or department. A cost driver is the cause of the cost, such as inspection count. Drivers are used to assign cost to cost objects.

What are the types of cost drivers in activity based costing?

Cost drivers are often grouped as volume-based and activity-based. Volume-based drivers move with output, such as machine hours. Activity-based drivers move with work done, such as number of set-ups or purchase orders.

Is a cost driver always a cost?

No. A cost driver is a measure of activity or volume, such as hours or number of orders. The cost is what it explains, such as rent or inspection cost.