Feet to Kilometers Calculator

Aviation, meteorology, and mountaineering routinely express distances and altitudes in feet, while the rest of the world — and all scientific disciplines — use kilometers. Converting between the two is a daily task for pilots reviewing weather reports, hikers comparing mountain heights with international databases, engineers working on cross-border infrastructure, and geographers translating survey data. One foot is defined as exactly 0.3048 meters, and one kilometer is exactly 1,000 meters, so the feet-to-kilometers factor is the exact figure 0.0003048. Because both underlying definitions are exact, this is a lossless conversion with no approximation. This calculator multiplies any foot value by 0.0003048 and returns the result to six decimal places, preserving enough precision for both small residential measurements and large geographic distances like mountain heights or flight paths.

Kilometers = Feet × 0.0003048. The factor is derived in two steps: one foot equals exactly 0.3048 meters by international definition (established in 1959), and one kilometer equals exactly 1,000 meters by SI definition. Dividing 0.3048 by 1,000 yields the exact feet-to-kilometers factor of 0.0003048. Because both source definitions are exact integers or defined decimals, the conversion carries no approximation error — any rounding in the output is only for display purposes. For large altitude values such as airplane cruising altitudes around 35,000 feet, the result (roughly 10.67 km) aligns with the commonly quoted metric equivalent. The calculator returns six decimal places so that short measurements still display a meaningful result rather than collapsing to zero.