Change order markup calculator
Prices a change order the way the contract does — extra quantity at the agreed unit price, changed work at cost plus overhead and profit — and shows the days it adds.
Change order markup calculator: run the calculator
Price the change order
Every field starts filled, so a figure is on screen before you type. Change a value and the result and every intermediate step follow it.
Change order = quantity part + direct cost raised by job overhead, home office overhead and profit. The quantity part is what the measured quantity bills, minus contract quantity times contract unit price.
Change order amount and time extension
Change order, net: $20,650.00
Contract quantity at the contract rate: 500.00 × $42.00 = $21,000.00
Quantity at the new rate: 140.00 × $36.50 = $5,110.00
Measured quantity billed: $26,110.00
Quantity part of the change order: $5,110.00
Direct cost, self-performed: $8,400.00
Self-performed work with the total markup: $8,400.00 + 20% = $10,080.00
Subcontracted work with its markup: $5,200.00 + 5% = $5,460.00
Changed and additional work priced: $15,540.00
Sales tax: 0% = $0.00
Change order including tax: $20,650.00
Contract sum after the change, net: $440,650.00
Share of the contract sum: 4.92%
Added effort in working days: 7
Time extension in calendar days: 10
Contract period after the change, in calendar days: 190
Share of the contract period: 5.56%
Every unit past the contract quantity bills at the new rate, and a shortfall simply bills less. No compensation is calculated.
One line item is priced here. A change order across several items is calculated line by line and then totaled.
Change order markup calculator: what it answers
A change order is two different claims wearing one name. Extra or reduced quantity is settled against the contract unit price, and only the part beyond an agreed threshold earns a renegotiated rate. Changed or additional work is built up from its own direct cost — labor, material, plant, subcontractor — and carries the job overhead, home office overhead and profit the contract allows. The calculator keeps both halves apart and then adds them.
Most disputes on a change order are not about the direct cost. They are about the markup that sits on top of it, about work already subcontracted, and about how many days the change buys. AIA A201 leaves the percentages to the agreement, so a contract that names 10 percent overhead and 10 percent profit still has to say whether profit is taken on cost alone or on cost plus overhead. This calculator makes that choice visible.
Change order markup calculator: how the result is worked out
Quantity first. Work up to the threshold is paid at the contract unit price; anything above it is paid at the renegotiated price, and the difference against the original contract quantity is the quantity part of the change. Cost next. Direct cost of self-performed work is raised by job overhead, then by home office overhead, then by profit, each step applied to the running total. Subcontracted cost carries its own single markup. The two parts are added.
Schedule is the half that gets forgotten. Additional labor hours divided by crew size and by hours worked per day gives working days; the calculator converts those to calendar days on a five-day week, because a contract completion date runs on calendar days. Compare the two shares the result gives you — the change as a percentage of the contract sum, and the extension as a percentage of the contract period. When the time share is the larger one, the markup is not the problem.
Change order markup calculator: what the result assumes
The markup percentages are yours to enter. No code, contract form or trade association fixes them; ten percent overhead with ten percent profit is a common clause, not a legal rate.
Extra quantity is measured against the original contract quantity, so the figure is the change against the signed sum. If the item has already been changed once, enter the currently agreed quantity instead.
The tolerance band works in both directions. Below it, the calculator raises the unit price so the omitted quantity still carries its share of overhead — an equitable adjustment your contract has to allow, as the federal variation-in-estimated-quantity clause does.
The time extension assumes the added hours cannot be absorbed by the crew already on site, that the crew works a five-day week, and that the work sits on the critical path. Running in parallel with another trade, it extends the job less.
Sales tax is left at zero. Whether a change to a construction contract is taxable, and at what rate, is set by the state and sometimes by the county.
Change order markup calculator: questions and answers
What is a normal markup on a change order?
Ten percent overhead and ten percent profit is the figure most contracts name, and public work often caps the subcontracted portion lower, around five percent. It is a contract term, not a standard rate. Read the clause before you price the change, because the cap usually applies per tier.
Is overhead and profit compounded or added?
Both are used. Adding them gives twenty percent on ten and ten; compounding profit onto cost plus overhead gives twenty-one. On a change worth forty thousand dollars in direct cost that difference is four hundred dollars. The calculator switches between the two so you can price the way your contract reads.
Does a change order automatically extend the completion date?
No. Most contracts require the extension to be claimed in the change order itself, in writing, within a notice period. A change order signed for money alone leaves the original date in force, and liquidated damages then run against work the owner asked for.
Change order markup calculator: use it on your own projects
Inside Home Builder Software the same calculation reads the project file, so the figure carries the budget, the awards and the invoices behind it instead of asking you to retype them.