Convert Foot (ft) to Chain (US Survey) (ch (US)) instantly.
About these units
Foot (ft)
A foot, equal to 12 inches, has been used for thousands of years and likely originated from the length of a human foot. Though early definitions varied, the modern standard foot—established internationally in 1959—provides a stable and consistent reference. The foot remains the foundation of architectural and construction measurements in the United States, influencing everything from lumber dimensions to ceiling heights and room layouts. Because the foot is intuitively relatable to human scale, people often estimate heights, furniture sizes, and walking distances in feet. In aviation, altitude is universally measured in feet worldwide, even in countries that otherwise use metric units—an unusual but deeply embedded global convention. The foot's persistence shows how cultural inertia can remain strong even when a unit predates modern scientific measurement.
Chain (US Survey) (ch (US))
The US Survey Chain is defined as 66 US Survey Feet (~20.1168 meters), aligning with the historic Gunter's chain but adapted to the US survey foot. It is used primarily in cadastral surveys, property delineation, and historical land records. Surveyors employ the chain for practical measurements of fields, lots, and infrastructure layouts. The unit's subdivision into 100 links simplifies area calculation, as 10 square chains equal one acre, maintaining continuity with older surveying systems. Even today, engineers and surveyors working with legacy data encounter the US survey chain in historical deeds, maps, and legal descriptions. Its precision ensures consistency when reconciling pre-modern measurements with modern coordinates.