Contract Penalty Calculator

How Contract Penalty Clauses Work

A contract penalty (also called a liquidated damages clause) is a pre-agreed amount one party pays the other if they breach a specific term — most commonly a deadline. Courts enforce these clauses when the amount is a genuine pre-estimate of loss, not a punishment.

Basic penalty formula:

Total Penalty = Daily Rate × Number of Days Late

Worked example:

A construction contract sets a $500/day penalty for late delivery. The project finishes 12 days past the deadline.

Total Penalty = $500 × 12 = $6,000

Penalty cap example:

Most contracts include a maximum cap, often expressed as a percentage of the contract value:

Max Penalty = Contract Value × Cap Percentage

If the contract is worth $200,000 and the cap is 10%:

Max Penalty = $200,000 × 10% = $20,000

Even if delays total 60 days ($30,000), only $20,000 is collectible.

Common penalty structures by contract type:

• Construction: $500–$5,000/day depending on project scale
• Software delivery: fixed milestone penalties (e.g., $2,000 per missed sprint)
• Lease termination: typically 1–3 months’ rent
• Service agreements: percentage of monthly fee per day of outage

Key legal principles:

• Liquidated damages vs. penalties — in many jurisdictions (UK, Australia), pure penalty clauses are unenforceable; amounts must represent genuine loss estimates
• Force majeure clauses often suspend penalty accrual for events outside the breaching party’s control (weather, pandemics, supply chain failures)
• Notice requirements — the non-breaching party may need to issue written notice before penalties begin accruing

Always have a contract attorney review penalty clauses before signing large agreements.