Convert Hand (hand) to Gigameter (Gm) instantly.
About these units
Hand (hand)
The hand is a traditional unit of length equal to 4 inches, historically used to measure the height of horses. Its origins go back thousands of years, when people commonly relied on body-based measurements. While early hands varied from culture to culture, the modern standardized hand—set at exactly 4 inches—was adopted to bring uniformity to equine measurement worldwide. When measuring a horse, the height is taken at the withers, the ridge between the shoulder blades, because this location provides a stable and consistent point unaffected by head movement. Horse heights are often written in a mixed-unit style: for example, "15.3 hands" means 15 hands plus 3 inches, not 15.3 × 4 inches. Though rarely used outside the world of horsemanship, the hand has become deeply embedded in equestrian culture. It provides a system that is intuitive, easy to visualize, and respectful of longstanding tradition. In modern times, even highly scientific equine breeding and veterinary studies continue to quote measurements in hands.
Gigameter (Gm)
A gigameter, one billion meters (10⁹ m), moves firmly into interplanetary territory. Astronomers use gigameters to express distances within the solar system, such as the average separation between planets or the orbital paths of spacecraft. For example, the Earth–Moon distance (~384,000 km) can be expressed as 0.384 Gm, and distances to nearby planets often fall in the range of tens or hundreds of gigameters depending on orbital positions. The gigameter is particularly useful in scientific models where distances are massive but still fall short of interstellar scales. It reduces the need for unwieldy scientific notation and gives researchers a manageable unit for calculations involving gravitational fields, orbital dynamics, and space mission planning.