Quantum Valebant

Quantum Valebant is a legal principle used to determine the value of goods or services provided when there is no existing contract stipulating a price. It allows a party to recover the reasonable value of goods or services conferred to another party, focusing on the fair market value at the time of the delivery.

The maxim originates from Roman law where it was used to resolve disputes involving the payment for goods or services absent an agreed price, emphasizing a fair settlement based on value received. This principle has been adopted in various legal systems and continues to hold importance in contractual disputes.

In modern law, Quantum Valebant is often invoked in cases of quasi-contracts or unjust enrichment, where one party benefits at the expense of another without a formal agreement. Courts apply this principle to determine compensation by assessing the fair market value of the benefits provided.

• A contractor completes work on a home, but the parties never agreed on a payment amount; the contractor can claim payment based on the reasonable market value of the work done.
• After a company mistakenly delivers goods to the wrong party, the recipient may be required to pay for those goods based on what they are reasonably worth, despite the absence of a sale agreement.

• Mackenzie v. H. Clanfield (1838) where the principle was utilized to assess the value of improvements made under an unenforceable agreement.