Contract Damages Calculator
Estimates damages owed when a contract is breached using the expectation-interest method — undelivered contract value plus incidental costs. Useful for businesses, contractors, and attorneys evaluating a breach claim before filing or settling.
Last updated: May 2026
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About this calculator
When a contract is breached, the non-breaching party is entitled to be 'made whole' through expectation damages — the financial position they would have occupied had the contract been fully performed. This calculator uses: damages = (contractValue × (1 − completionPercent / 100)) + additionalCosts. Variables: contractValue (the full agreed-upon price), completionPercent (the percentage of work delivered or value received before breach, 0–100), additionalCosts (incidental and consequential expenses caused by the breach — replacement contractor premiums, emergency procurement, expedited shipping, temporary staffing). The first term represents the undelivered portion of contract value (the expectation gap), and the second term captures collateral losses the breach forced you to absorb. Together they reflect the two pillars of contract damages: lost value from non-performance and induced costs from rectifying the breach. Edge cases: this formula does not handle liquidated damages clauses (which set a contractual cap), limitation-of-liability provisions, lost profits beyond replacement cost, or punitive damages (almost never available in contract). It also does not subtract the value of partial performance that has independent worth, nor does it account for the duty to mitigate — failing to seek a reasonable replacement reduces the recoverable amount.
How to use
Example 1: $50,000 construction contract abandoned at 40% completion; you spent $3,000 finding a replacement. Step 1 — undelivered 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. Verify: you paid for full performance but received only 40% — the gap plus rectification costs equals what restores you to your contracted-for position. Example 2: $20,000 software development contract breached at 75% completion; replacement vendor cost $4,000 more than the original. Step 1: $20,000 × (1 − 75/100) = $20,000 × 0.25 = $5,000. Step 2: $5,000 + $4,000 = $9,000. Verify: undelivered work cost more from a substitute (the 'cover' damages doctrine of UCC §2-712), and total recovery reflects that excess.
Frequently asked questions
How is the undelivered portion of a contract calculated in a breach claim?
The undelivered portion equals the total contract value multiplied by the percentage of work not yet performed. If a $100,000 contract was 75% complete at breach, the undelivered value is $25,000. This represents the expectation interest — the value you paid for and did not receive. Courts may also examine whether the completed portion has independent value to you, in which case the calculation becomes more nuanced. For construction matters, partial work that requires complete redesign or demolition may be treated as zero-value despite physical completion.
What additional costs can be included in a breach of contract damages claim?
Additional costs typically include expenses incurred because of the breach: hiring a replacement vendor at a higher price (cover damages), expedited shipping, temporary staffing, emergency repairs, and storage fees while finding a substitute. These are called incidental or consequential damages and are recoverable if they were foreseeable at contract formation (the Hadley v. Baxendale rule). Lost profits from downstream business activities are also recoverable if foreseeable — but must be proven with reasonable certainty. Keep all invoices, replacement contracts, and written communications, since documentation requirements are strict. Not all jurisdictions allow consequential damages unless the contract explicitly permits them, and many contracts limit them via waiver clauses.
Does the non-breaching party have a duty to mitigate contract damages?
Yes — under the mitigation doctrine, the non-breaching party must take reasonable steps to reduce losses after a breach occurs. If a contractor abandons a project, the owner should promptly solicit replacement bids rather than letting the work remain incomplete and damages accrue. Failure to mitigate reduces the damages award by the amount that reasonable efforts could have avoided. Keep written records of mitigation attempts — bid requests, vendor selection notes, time-stamped emails — to demonstrate reasonableness. Mitigation does not require accepting unreasonable substitutes or paying premium prices for emergency replacement, but it does require active, good-faith effort.
What are common mistakes when estimating breach of contract damages?
Inflating the completion percentage understates the undelivered portion and undersells your claim — courts often require independent third-party assessment of percent complete for construction matters. Including speculative future profits that cannot be proven with reasonable certainty leads to claim denial under the foreseeability rule. Ignoring liquidated-damages clauses in the contract overrides the formula entirely — if the contract specifies $500/day liquidated damages, that is the recoverable amount regardless of actual loss. Forgetting limitation-of-liability provisions (common in software and service contracts) can render large damages claims worthless. Failing to subtract amounts already paid that produced no value double-counts the loss, and double-counting cover damages with undelivered-value damages is a common arithmetic error.
When should I NOT use this contract damages calculator?
Contracts with liquidated damages clauses follow the contractual amount, not actual damages — use the contract terms instead. Sale-of-goods cases governed by UCC Article 2 have specific damages formulas (cover, market-price differential, lost profits) that differ from this general approach. Real estate purchase agreements typically use earnest-money forfeiture or specific performance, not multiplier damages. Employment contracts trigger statutory minimums and tort overlay that this formula ignores. Personal-service contracts (artists, consultants) where the unique skill cannot be replaced may merit specific performance instead of damages. Government contracts follow Federal Acquisition Regulation rules with their own remedies. For any of these scenarios, consult counsel familiar with the specific contract type before relying on this estimate.