What is the legal standard of proof in most US civil cases?

The legal standard of proof in most U.S. civil cases is the preponderance of the evidence.

This standard asks the fact-finder to decide whether a claim is more likely true than not true. It is often described as requiring the party with the burden of proof to show a greater-than-50-percent likelihood, though courts generally do not calculate an actual numerical probability.

The rule reflects the ordinary balance of civil litigation: disputes usually concern money, property, contracts, injuries, or other private rights rather than criminal punishment. The plaintiff typically bears the burden of proving the elements of the claim, while the defendant may carry the burden for an affirmative defense.

The standard is lower than beyond a reasonable doubt, which applies to criminal convictions. Clear and convincing evidence is an intermediate standard used in some civil matters, such as certain fraud, parental-rights, or government proceedings. The exact rule can vary by jurisdiction and claim.