Cost Accounting Standard 2 (CAS-2): Capacity Determination
A clear guide to CAS-2 capacity determination, including installed, practical, normal and actual capacity and why capacity affects overhead absorption.
Cost Accounting Standard 2 (CAS-2) is about capacity determination. It explains how an entity should determine the capacity of a facility that produces goods or provides services, so costs can be assigned and absorbed on a consistent basis.
This page is about CAS-2 specifically. For the broader overview, see our guide to cost accounting standards. For the related overhead standard, see Cost Accounting Standard 3.
What does CAS-2 cover?
CAS-2 deals with the principles and methods used to classify and determine capacity. The official ICMAI standard frames capacity determination as part of ascertaining the cost of a product or service and presenting that information in cost statements.
In plain English, CAS-2 helps answer questions such as:
- What is the facility capable of producing or servicing?
- What capacity level should be used for cost absorption?
- How should normal downtime, practical constraints and actual use be reflected?
- What capacity information should be disclosed in cost statements?
Why capacity determination matters
Capacity affects how fixed and semi-fixed costs are absorbed. If capacity is overstated, unit costs may look artificially low. If capacity is understated, unit costs may look too high. Either error can distort pricing, profitability analysis, inventory valuation, contract costing and performance reporting.
That is why CAS-2 sits close to overhead allocation. Capacity is one of the foundations used when assigning production or operation overheads to products, services or cost objects.
Key capacity terms in CAS-2
The exact definitions should always be checked against the current ICMAI text, but the practical concepts are:
- Installed capacity: the maximum productive capability based on the facility, equipment or service setup.
- Practical capacity: installed capacity adjusted for unavoidable interruptions and practical operating limits.
- Normal capacity: the level expected over a period under normal circumstances, after considering demand, maintenance and operating conditions.
- Actual capacity utilisation: the capacity actually used during the period.
- Idle capacity: capacity that exists but is not used.
CAS-2 and overhead absorption
Capacity determination matters because overheads are often absorbed using a capacity base. For example, fixed production overhead may be spread across normal capacity rather than only actual output. That prevents abnormal low utilisation from loading too much fixed cost into each unit.
This also helps management separate operating efficiency from market demand or downtime issues. A facility may have high installed capacity but lower normal capacity because of realistic operating constraints. CAS-2 gives a structured way to document that difference.
Example: why capacity changes unit cost
Suppose fixed production overhead is GBP 120,000. If normal capacity is 60,000 units, the fixed overhead absorption rate is GBP 2 per unit. If the business incorrectly uses 40,000 units as the capacity base, the rate becomes GBP 3 per unit. That single capacity assumption changes product cost and may affect pricing, margin analysis and stock valuation.
The point of CAS-2 is not the arithmetic alone. It is the discipline of using a reasonable, consistent and disclosed capacity basis.
What should be disclosed?
Capacity-related disclosures usually help readers understand the basis used, changes from the previous period, and the reasons for under-utilisation or abnormal capacity effects. Useful disclosures include:
- the basis used to determine capacity;
- installed, practical, normal and actual capacity where relevant;
- changes in capacity and the reasons for those changes;
- treatment of idle capacity or abnormal costs;
- whether capacity is measured in units, hours or another appropriate measure.
CAS-2 vs the broad cost accounting standard topic
CAS-2 should not be treated as a generic page for every cost accounting standard. It has a specific job: capacity determination. The broader topic includes cost classification, allocation, standard costing, compliance frameworks and other standards. That broad topic belongs on the cost accounting standards keeper page.
Study accounting standards with Learnsignal
If you want to strengthen your practical accounting and reporting knowledge, explore Learnsignal's online CPD courses for accountants and finance professionals.
This page was last updated:
Johnny Meagher
Expert Tutor at Learnsignal
Qualified professional with years of experience in teaching and helping students achieve their accounting qualifications.
View all posts by Johnny Meagher

