Convert Drop (drop) to Acre-Foot (ac*ft) instantly.
About these units
Drop (drop)
The drop is one of the oldest fluid measures and originally referred simply to the amount of liquid that naturally forms at the end of a dripping vessel. Because drop size depends on viscosity, surface tension, temperature, and orifice size, early medicine found drops inconsistent and unreliable. Modern medicine and chemistry sometimes define a drop as 0.05 mL, but this is only a convention used for standardized droppers—real drops can vary significantly. Despite its imprecision, the drop survives in everyday language, aromatherapy, essential oils, and household instructions ("add a few drops"). It exemplifies humanity's earliest attempts to quantify small volumes before scientific instrumentation enabled precise micro-measurement.
Acre-Foot (ac*ft)
An acre-foot represents the volume of water needed to cover one acre of land to a depth of one foot—approximately 1,233.48 cubic meters or 325,851 gallons. This unit is foundational in water resource management throughout the western United States, where large-scale irrigation, reservoir planning, and drought analysis depend on acre-foot measurements. For example, major reservoirs like Lake Mead and Lake Powell hold billions of acre-feet. In agriculture, irrigation districts track water rights and allocations using acre-feet, making it a key component of water law. Its scale is ideal for representing the enormous water needs associated with farming, urban expansion, and environmental preservation.