Which allocation base is most accurate?

Activity-based costing, because it uses a separate driver for each cost pool. It is also the most expensive to maintain. For most small businesses two or three pools with obvious drivers — space by square footage, admin by order count, production overhead by machine or labour hours — captures the majority of the accuracy for a fraction of the work.

Should I allocate overhead before pricing?

Not for the floor price. Price the floor off incremental cost, since a sale above incremental cost adds contribution regardless of allocation. Use allocated cost to check that long-run prices cover the whole cost structure. Pricing off allocated cost during a volume decline raises prices exactly when demand is weakest.

How do I allocate overhead to a service business?

Billable hours is usually the right driver, since overhead in a service firm scales with delivery capacity. Divide total overhead by expected billable hours to get an overhead rate per hour, then add it to direct delivery cost. At 1,320 billable hours and $132,000 of overhead the rate is $100 per hour.

What if a product cannot cover its allocated overhead?

Check contribution first. A product contributing $40,000 while carrying $60,000 of allocated overhead still leaves the business $40,000 better off than deleting it, unless the freed capacity has a better use. The allocated loss is a signal to reprice or reduce the resource it consumes, not an automatic case for removal.

Business & Tax

Allocated Overhead: How to Fairly Assign Shared Costs to Products (2026)

Master the allocated overhead calculation to ensure fair cost distribution among products. Choose the right base to reflect true profitability.

By FreeCalculators Editorial · Published 2026-09-01 · Updated 2026-09-04 · 4 min read · 916 words

Allocated overhead is the share of shared, non-traceable cost assigned to a product, service line, or department. Rent, administration, insurance, and management salaries do not attach to any single unit, so a base — an allocation driver — is chosen to spread them. The total profit of the business is unaffected by that choice; which products appear profitable is affected enormously.

The Five Bases and What Each One Rewards

A good base is the one that causes the cost. If overhead rises because more labour hours are worked, labour hours is the correct driver; if it rises with order count, use orders.

Overhead allocation bases and the circumstances that make each one misleading.
Allocation base	Mechanism	Distorts when
Revenue share	Overhead in proportion to sales dollars	High-price products use no more resource than cheap ones
Direct labour hours	Overhead per hour worked on the product	Automation means machines, not people, drive cost
Machine hours	Overhead per hour of equipment time	Labour-intensive lines use little machine time
Headcount or square footage	Overhead by space or people occupied	Space use is unrelated to output volume
Activity-based costing	Separate driver per activity pool	Complexity exceeds the value of the extra precision

The Same Overhead, Two Bases, Opposite Conclusions

$180,000 of overhead across two product lines (2026)

                Standard line: 12,000 units, $600,000 revenue, 6,000 labour hours
Custom line: 1,500 units, $300,000 revenue, 9,000 labour hours
Revenue-share base: standard 66.7% = $120,000, custom 33.3% = $60,000
Per unit: standard $10.00, custom $40.00
Labour-hour base: $180,000 / 15,000 hours = $12.00 per hour
Standard: 6,000 x $12 = $72,000, or $6.00 per unit
Custom: 9,000 x $12 = $108,000, or $72.00 per unit
Custom overhead per unit differs by $32 depending only on the base chosen

The custom line consumes 60% of the labour hours while generating 33% of revenue. Revenue-share allocation understates its cost by $48,000 a year, which is often the difference between a line that looks like the future of the business and one that is quietly subsidised by the standard range.

Choosing and Testing a Base

List the overhead pools separately — facilities, administration, selling, technology — rather than treating overhead as one number.
For each pool, ask what makes it grow: floor space, headcount, order count, machine time, or engineering changes.
Pick the driver you can measure without a new system; a slightly imperfect measurable driver beats a perfect unmeasurable one.
Run the allocation under two different bases and compare the product rankings.
If the ranking flips, investigate before acting — the flip means the decision depends on an accounting choice, not on the business.
Document the base and revisit it annually, because automation and product mix both change what drives cost.

What the Tax Rules Require

For businesses that produce or resell goods, allocation is not purely a management choice. The IRS uniform capitalization rules require certain indirect costs to be capitalised into inventory rather than expensed as incurred, and they permit several allocation methods, including specific identification, burden rate, and standard cost, provided the method is applied consistently. The practical consequence is that most product businesses already maintain an allocation for tax purposes, and the cheapest path is to reuse a defensible driver for both purposes rather than maintaining two incompatible views.

Keep contribution and allocated profit on the same report, in adjacent columns. Decisions about pricing and product deletion belong to the contribution column; decisions about long-run capacity belong to the allocated one.

Frequently asked questions

Which allocation base is most accurate?: Activity-based costing, because it uses a separate driver for each cost pool. It is also the most expensive to maintain. For most small businesses two or three pools with obvious drivers — space by square footage, admin by order count, production overhead by machine or labour hours — captures the majority of the accuracy for a fraction of the work.
Should I allocate overhead before pricing?: Not for the floor price. Price the floor off incremental cost, since a sale above incremental cost adds contribution regardless of allocation. Use allocated cost to check that long-run prices cover the whole cost structure. Pricing off allocated cost during a volume decline raises prices exactly when demand is weakest.
How do I allocate overhead to a service business?: Billable hours is usually the right driver, since overhead in a service firm scales with delivery capacity. Divide total overhead by expected billable hours to get an overhead rate per hour, then add it to direct delivery cost. At 1,320 billable hours and $132,000 of overhead the rate is $100 per hour.
What if a product cannot cover its allocated overhead?: Check contribution first. A product contributing $40,000 while carrying $60,000 of allocated overhead still leaves the business $40,000 better off than deleting it, unless the freed capacity has a better use. The allocated loss is a signal to reprice or reduce the resource it consumes, not an automatic case for removal.

Calculators in this guide

Profit Per Unit Calculator
Easily calculate the profit per unit sold after all costs. This tool helps you assess the profitability of your products effectively.
Gross Profit Margin Calculator
Calculate your gross profit margin easily. This tool helps you assess pricing power and production efficiency for informed business decisions.
Break-Even Revenue Calculator
Discover the monthly revenue needed to break even. This calculator helps you identify the sales target to cover all your costs effectively.
1031 Exchange Calculator
Discover the tax deferral benefits of a 1031 exchange with our easy-to-use calculator for your investment properties.