Calculus of negligence

In the United States, the calculus of negligence, also known as the Hand rule, Hand formula, or BPL formula, is a term coined by Judge Learned Hand and describes a process for determining whether a legal duty of care has been breached (see negligence). The original description of the calculus was in United States v. Carroll Towing Co.,[1] in which an improperly secured barge had drifted away from a pier and caused damage to several other boats.