Hand formula

In the United States, the Hand formula, also known as the Hand rule, calculus of negligence, or BPL formula, is a conceptual formula created by Judge Learned Hand which 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., in which an improperly secured barge had drifted away from a pier and caused damage to several other boats.