Contract Damages Calculator
Estimate damages owed when a contract is breached, based on incomplete performance and additional out-of-pocket costs. Useful for attorneys, contractors, and businesses evaluating a breach of contract claim.
About this calculator
When a contract is breached, the non-breaching party is entitled to be made whole — typically through expectation damages. This calculator uses: Damages = (contractValue × (1 − completionPercent / 100)) + additionalCosts. The first term represents the undelivered portion of the contract's value. For example, if 60% of work was completed, the breaching party still owes value for the remaining 40%. The second term captures incidental or consequential costs the non-breaching party had to incur as a result of the breach — such as hiring a replacement contractor or emergency procurement. Together, these two components reflect both the direct loss from non-performance and the collateral costs triggered by it. Courts may adjust these amounts based on mitigation efforts, foreseeability, and applicable state law.
How to use
Suppose a contractor was hired for a $50,000 project but abandoned it after completing 40% of the work, and you incurred $3,000 in costs to secure a replacement. Step 1: Uncompleted portion = $50,000 × (1 − 40/100) = $50,000 × 0.60 = $30,000. Step 2: Add additional costs = $30,000 + $3,000 = $33,000 in estimated damages. Adjust the completion percentage to reflect what was actually delivered. Higher additional costs increase the claim proportionally.
Frequently asked questions
How is the undelivered portion of a contract calculated in a breach of contract case?
The undelivered portion is calculated as the total contract value multiplied by the percentage of work that was not completed. If a $100,000 contract was 75% complete at the time of breach, the remaining undelivered value is $25,000. This represents the expectation interest — what the non-breaching party paid for and did not receive. Courts may also examine whether the completed portion has independent value or needs to be redone.
What additional costs can be included in a breach of contract damages claim?
Additional costs typically include expenses the non-breaching party had to incur because of the breach, such as hiring a replacement vendor, expedited shipping, temporary staffing, or emergency repairs. These are known as incidental or consequential damages and are recoverable if they were foreseeable at the time the contract was formed. Documentation is critical — keep all invoices, contracts with replacement vendors, and written communications. Not all jurisdictions allow consequential damages unless the contract explicitly permits them.
Does the non-breaching party have a duty to reduce contract damages after a breach?
Yes — under the legal principle of mitigation, the non-breaching party has a duty to take reasonable steps to reduce their losses after a breach occurs. For example, if a contractor abandons a project, the owner should promptly seek a replacement rather than allowing the work to remain incomplete indefinitely. Failure to mitigate can reduce the damages award even if the breach itself was clear-cut. Keep records of your mitigation efforts to demonstrate reasonableness in any subsequent legal proceeding.