Change Order Calculator
Calculate change order step by step: Net = added − deleted.
In short
Formula: Net = added − deleted. Change order = net × (1 + overhead%) × (1 + markup%). Revised contract = current + change order.
What this calculator does
Calculate change order step by step: Net = added − deleted. Worked example, questions and limitations included.
Use it to turn Currency, Current contract value, Direct cost of added work, Direct cost of deleted work, and the other shown inputs into a checked result you can compare, copy, or rerun with different assumptions.
The page shows the formula, a numeric worked example, and the assumptions that affect this construction calculation.
Inputs and what they mean
- Currency
- — choice value.
- Current contract value
- — number value.
- Direct cost of added work
- — number value.
- Direct cost of deleted work
- — number value.
- Overhead on net change
- — number value.
- Markup on net change
- — number value.
How to use it
- Enter each value in the unit shown next to the box (use the unit converter first if your numbers are in other units).
- Check the breakdown to see every intermediate step.
- Read the limitations before relying on the result.
Formula
Price added and deleted work with the construction cost calculator first.
Some contracts limit markup on deductive changes — check yours.
A negative result is a credit to the owner.
Net = added − deleted. Change order = net × (1 + overhead%) × (1 + markup%). Revised contract = current + change order.
Inputs used: Currency, Current contract value, Direct cost of added work, Direct cost of deleted work, Overhead on net change, Markup on net change.
Worked example
Extra footing, deleted pathway
- Net = 5,000.
- × 1.10 = 5,500; × 1.10 = 6,050.
- Revised contract = 256,050.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Reference price tables
No reference prices are configured. Enter your own prices and rates — this site never assumes them.
Limitations and assumptions
- Same percentages on additions and deletions.
- No time-related costs.
- Contract terms govern the final value.
- Results are estimates for planning and learning. Real designs, installations and bids must be checked by a qualified, licensed professional against the codes that apply where you work.
- The result depends on the values you enter for this change order calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.
Common questions
Can a change order be negative?
Yes. When deleted work exceeds added work, the result is a credit that reduces the contract.
Should markup apply to deleted work?
Contracts differ. Some give full credit including markup; others give only direct cost. Follow your contract.
What about schedule impact?
Time extensions and delay costs are negotiated separately and not calculated here. Check the formula, example, and limitations on this page before using the result for a real construction decision.
How do I use the Change Order Calculator?
Enter the required values for Currency, Current contract value, Direct cost of added work, Direct cost of deleted work, Overhead on net change, and the other fields shown. The calculator applies the formula on this page and shows the main result with any supporting breakdown so you can check the arithmetic.
What formula does the Change Order Calculator use?
Net = added − deleted. Change order = net × (1 + overhead%) × (1 + markup%). Revised contract = current + change order. The visible formula section above lists the calculation path and the edge cases the page handles, so the result can be checked without relying on the form alone.
Can the Change Order Calculator be used for exact decisions?
Use it as a calculation aid, not as a substitute for checking the underlying rule, contract, policy, or professional advice that applies to your situation. When a result depends on local rules, personal details, prices, or dates, enter those values yourself and confirm them before acting.
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