Table of Content

Activity Base

An activity base is the measure used to allocate a cost based on the activity that causes or explains that cost.

In management accounting, an activity base helps turn shared costs into more meaningful numbers. Instead of spreading a cost evenly across every job, product, or department, the business chooses a driver that better reflects how the cost is used.

You may also hear the term “cost driver”. The idea is similar: find the activity that causes the cost to happen.

Where Activity Base Appears

Activity bases appear in activity-based costing, activity-based budgeting, job costing, project reporting, manufacturing reports, service pricing, and internal management accounts.

They also connect with allocated costs, allocations, budget, and CapEx to Revenue Ratio when businesses are trying to understand what drives cost or investment.

How Activity Base Works In Practice

The activity base should match the cost as closely as practical. Examples include:

  • machine hours for equipment-related overheads
  • labour hours for labour support costs
  • number of invoices for billing administration
  • number of deliveries for dispatch costs
  • square metres for rent or storage costs

The better the fit, the more useful the allocation.

Simple Example

A workshop pays $6,000 a month for machine maintenance. Product A uses 200 machine hours and Product B uses 100 machine hours. Machine hours are the activity base.

The business allocates two-thirds of the maintenance cost to Product A and one-third to Product B because Product A used twice as much machine time.

Why Activity Base Matters

Choosing the wrong activity base can distort profit by product, job, customer, or department. A product may look profitable only because it is not carrying its fair share of overheads.

The goal is not perfect precision. It is a fairer view of cost, so pricing, budgeting, and planning decisions are less guessy.

How Gimbla Can Help

Gimbla helps keep the transaction records behind allocations organised. When invoices, bills, receipts, bank entries, and project records are cleaner, it is easier to choose practical activity bases and review the results with your accountant.

Helpful Gimbla Guides

In Short

An activity base is the practical measure used to spread a shared cost. Pick the activity that best explains the cost, then use it consistently.