Unit Converters

ConvertLab guides

Plain-language answers to unit converters questions, written from the same sourced data behind ConvertLab. Every guide lists its sources and the date it was last updated.

• Updated June 10, 2026

  Is an inch exactly 2.54 centimeters?

  Yes — since 1959 the inch is defined as exactly 2.54 cm, pinning down foot, yard, mile, and pound with zero measurement error.