Free tool

Change order cost impact calculator

See how a change order shifts your blended project margin before you submit it for approval.

Enter a contract sum greater than $0.

See how Buildend tracks change orders against budget →

Estimate only. Blended margin = (original profit + CO profit) ÷ new contract total. Doesn't account for general conditions, retainage, or contract-specific fee structures.

Disclaimer: The calculators, assessments, and checklists on this page are provided by Buildend for general informational and planning purposes only. They are not a substitute for professional advice from a licensed engineer, accountant, attorney, or other qualified professional, and they should not be relied upon as the sole basis for any financial, structural, contractual, or safety-related decision. Results are estimates based on the values you enter and standard industry formulas or assumptions. They do not account for site-specific conditions, local building codes, contract terms, material specifications, or other factors that may materially affect actual outcomes. Buildend makes no warranty, express or implied, as to the accuracy, completeness, or applicability of any result produced by these tools. You are solely responsible for verifying all calculations, quantities, and figures with appropriate professionals — including your ready-mix supplier, structural engineer, accountant, and legal counsel — before relying on them for bidding, ordering materials, structural design, or contractual purposes. To the fullest extent permitted by law, Buildend disclaims all liability for any loss, damage, or claim arising from the use of, or reliance on, these tools.