Calculate change order costs with labor, materials, markup, and schedule impact analysis with approval workflow tracking.
A change that reads as one extra outlet on the drawings becomes a contract figure only when hours, rates, materials, and markup sit on the same sheet. This calculator builds a change order price from labor hours and pay rates, material and equipment costs, and a markup you set, then records the schedule impact - how many working days the change adds - beside the dollar total. The surprise is that markup is not profit: it also has to carry overhead, risk, and the cost of the delay, so a percentage that looks generous on a small change often thins out once overhead is paid.
A concrete input and expected output from the current implementation.
Input
Labor: 40 hours at $75/h. Materials: $2,500. Overhead: 10% on direct costs. Markup: 15% on the subtotal. Schedule impact: +2 working days on a project due in 12 weeks.
Expected output
Direct costs: $5,500 (labor $3,000 + materials $2,500). Overhead: $550. Subtotal: $6,050. Markup: $907.50. Change order total: $6,957.50. Revised completion: original due date + 2 working days.
40 hours x $75 = $3,000 labor, so direct costs total $5,500; overhead of 10% adds $550 and markup of 15% on the $6,050 subtotal adds $907.50, giving $6,957.50. The completion date shifts by the two entered working days - the calculator prices the change, it does not derive the delay.
Labor is hours times rate, summed with materials, equipment, and subcontract quotes into direct costs. Overhead and markup are percentages you set, and each step appears itemized, so you can read where every dollar was added rather than receiving a single back-of-envelope total. The final figure includes your markup, so it is the amount to present, not the raw cost of the work.
You enter the delay in working days and the tool restates the completion date against the original schedule. The priced change order then enters an approval workflow, so the figure is tracked as a decision record - who submitted it and what was decided - rather than left as a loose estimate on a spreadsheet.
Not directly. The markup has to cover overhead, risk, and any delay cost before anything becomes profit, and what percentage is defensible varies by trade, market, and contract - some contracts cap change order markup. Treat the rate as a business decision you set, not something the calculator derives.
Before, and that is the point of the approval tracking: price it, get it accepted, then execute. Pricing after the fact forfeits leverage, and many contracts do not obligate payment for work done without an approved change order. If work is already underway, price what was actually performed and flag the timing.
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