How to Calculate Construction Overhead and Markup in Canada

Ask ten contractors what percentage they add for "overhead and profit" and you will likely get ten different answers, and a fair number of them will not be entirely sure what the number is actually supposed to cover. That confusion is expensive. Underestimate overhead and a contractor can win jobs that quietly lose money. Misjudge markup and a bid comes in too high to win the work at all, or too low to make it worth doing. Getting both right starts with understanding what each one actually represents.

Overhead vs. Markup: The Core Difference

Overhead is the cost of operating a construction business and delivering a project that is not tied to a specific unit of material or labour hour. It is real cost, not profit, it just is not visible in a materials list or a labour schedule the way a stack of lumber or a day of framing is.

Markup, often used interchangeably with profit in everyday conversation, is the amount added on top of direct cost and overhead that represents what the business actually earns from doing the work. It compensates for risk, expertise, and the simple fact that a business needs to make money to survive and grow.

Put together, the basic pricing formula looks like this: Direct Cost (materials, labour, equipment) + Overhead (business and job-specific indirect costs) + Profit (markup) = Bid Price. Skipping or underestimating any one piece of that equation produces a number that looks competitive on paper and performs badly in practice.

The Two Types of Overhead

Overhead itself splits into two distinct categories, and mixing them up is one of the more common sources of pricing error.

General (Office) Overhead

General overhead is the cost of running the business itself, independent of any single project: office rent or a home office allocation, administrative and accounting staff, insurance premiums, licensing and professional fees, vehicles not assigned to a specific job, software subscriptions, and marketing. These costs exist whether the business has one active project or ten, and they need to be spread proportionally across all projects a contractor completes in a year.

Job (Project) Overhead

Job overhead, by contrast, is tied specifically to one job site: temporary site facilities, site supervision and project management time, equipment rental not billed directly to a cost line, permits and inspection fees, site security, temporary utilities, and cleanup. Unlike general overhead, it needs to be estimated project by project rather than applied as a flat percentage.

Typical Percentages by Project Type

There is no single correct number, but industry practice gives a reasonable range to work from.

Combined, most contractors land somewhere between 15% and 35% total on top of direct cost, with smaller residential work typically sitting at the higher end of that range and large-scale commercial or industrial work at the lower end, since bigger contracts spread fixed overhead across more dollars of direct cost.

Markup vs. Margin: A Common Mix-Up

This is where a surprising number of contractors lose money without realizing it. Markup is calculated as a percentage of cost. Margin is calculated as a percentage of the final selling price. They are not interchangeable, and using one number as if it were the other produces a real gap in expected profit.

For example, a 25% markup on a $100,000 direct cost produces a bid price of $125,000, which works out to a 20% margin, not 25%. A contractor aiming for a 25% margin on that same job actually needs to apply a 33.3% markup. Mixing these two calculations up, even by a small amount, compounds across every project a business runs in a year.

Why the Right Percentage Varies

Several factors push the right overhead and markup percentage up or down for a specific contractor or project.

Business size and volume. A larger contractor with more annual revenue spreads fixed general overhead across more projects, which can support a lower percentage markup per job while still covering total business costs.

Project risk. Complex, unfamiliar, or tight-schedule projects justify a higher markup to compensate for the added risk of something going wrong.

Market competitiveness. In a highly competitive bidding environment, contractors sometimes accept a thinner markup to win work, though this comes with real risk if overhead is not tracked carefully enough to know the actual break-even point.

Relationship and repeat business. Some contractors adjust markup for established clients or repeat work, weighing a slightly lower margin on any single job against lower marketing and business development cost over time.

Building It Into a Bid

Getting overhead and markup right starts with actually knowing a business's numbers rather than applying an industry rule of thumb by habit. That means tracking annual general overhead against annual revenue to calculate a realistic percentage, estimating job-specific overhead for each project individually rather than folding it into a flat rate, and deciding markup deliberately as a margin target rather than an arbitrary percentage pulled from a competitor's rumoured pricing.

An estimate that gets direct costs right but treats overhead and markup as an afterthought is only half finished. The number a contractor actually needs to hit to stay in business depends just as much on these two categories as it does on the price of lumber and the local labour rate.