Convert Inch (in) to Fathom (US Survey) (fath (US)) instantly.
About these units
Inch (in)
An inch is defined as exactly 25.4 millimeters, a precise metric-based definition that preserves its usefulness within imperial systems. Historically, the inch was based on the width of three barleycorns placed end-to-end, a charming relic of medieval measurement practices. Today, the inch is vital in manufacturing, woodworking, consumer electronics (e.g., screen sizes), and tooling standards across the US and partially in the UK. Its size is small enough to offer usable precision yet large enough to avoid unwieldy fractions for many everyday objects. Even in predominantly metric industries, certain products—such as plumbing parts, bicycle rims, and camera mounts—retain inch-based standards for compatibility. This persistence shows how technological ecosystems can outlive their measurement origins.
Fathom (US Survey) (fath (US))
The US Survey Fathom is defined as 6 US Survey Feet (~1.8288 meters), identical in proportion to the traditional fathom but scaled to the US Survey Foot. Maritime surveys, early river navigation, and hydrographic measurements relied on this unit for determining depths and plotting charts. In terrestrial applications, the fathom occasionally served as a practical measure for large structures or obstacles. Although less relevant in contemporary usage, understanding the US survey fathom is crucial for interpreting historical navigation data, nautical charts, and engineering projects using older measurement systems.