How our calculators work
Every calculator on this site runs the standard job costing formulas, no hidden assumptions. The core formula set:
- Loaded labor = hours × wage × (1 + burden %)
- Direct cost = loaded labor + materials + equipment + subcontractors + other
- Overhead = direct cost × overhead rate
- Total cost = direct cost + overhead
- Profit = contract price − total cost
- Net margin = profit ÷ contract price
- Markup = profit ÷ total cost
Margin is always profit as a percentage of price, and markup is always profit as a percentage of cost. The two are never treated as interchangeable.
The golden test case
Every calculator is tested against a fixed reference job before release and after every change. The reference: a $120,000 contract with 640 hours of labor at $34 per hour with a 28% burden, $31,000 in materials, $6,500 in equipment, $18,000 in subcontractors, $2,200 in other direct costs, and a 12% overhead rate. It must return a total cost of $95,819, profit of $24,181, margin of 20.2%, and markup of 25.2%. If the calculator returns anything else, the change is not shipped.
How figures in articles are verified
Figures in articles come from three sources, and the article makes clear which one you are looking at:
- Our calculators and product. Numbers like the golden test case above can be reproduced by using the tools on this site.
- Official sources. Where we cite a rule or a standard, we link to the issuing body, such as the IRS or a state agency.
- Illustrative examples. Practice ranges, such as typical labor burden percentages, are labeled as illustrative and are never presented as official statistics.
Review and update
Content is reviewed by a construction cost accountant and a project manager before publication. The last-reviewed date at the bottom of each page updates whenever the page changes. If you spot an error, tell us and we will correct it.