# Change Order Calculator

> Calculate change order step by step: Net = added − deleted.

Page: https://freecalculator.tech/tools/change-order-calculator
Last reviewed: 2026-11-03

## Formula

Net = added − deleted. Change order = net × (1 + overhead%) × (1 + markup%). Revised contract = current + change order.

- 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.

## Inputs

- 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

Contract 250,000; added 8,000; deleted 3,000; 10% overhead, 10% markup.
1. Net = 5,000.
2. × 1.10 = 5,500; × 1.10 = 6,050.
3. Revised contract = 256,050.

## 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.

### 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.

## 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.

## Sources

- OpenStax (Rice University) — https://openstax.org/details/books/contemporary-mathematics

## Cite this page

- APA: Free Calculator. (2026, November 3). Change Order Calculator. https://freecalculator.tech/tools/change-order-calculator
- MLA: "Change Order Calculator." Free Calculator, 3 Nov. 2026, https://freecalculator.tech/tools/change-order-calculator.
- Link: Change Order Calculator — Free Calculator, https://freecalculator.tech/tools/change-order-calculator