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Convert Foot to Light Year (ft to ly) instantly with accurate, readable results.
Use our Length Unit Converter to quickly convert between meters, kilometers, feet, inches, miles, and more. This powerful unit conversion tool supports both metric and imperial systems, making it ideal for travel, engineering, education, and everyday use. Whether you're calculating distances or comparing measurements, our length unit conversion calculator ensures fast and accurate results every time.
Foot (ft) — Imperial/US unit defined exactly as 0.3048 meters
Common for human height, room dimensions, and construction. Part of the feet–inches notation in building trades.
- Symbol: ft
- System: Imperial/US customary
- Exact relations: 1 ft = 0.3048 m = 30.48 cm = 304.8 mm (exact)
- Other relations: 1 ft = 12 in, 3 ft = 1 yd
- Typical examples: ceiling heights, floor plans, ladder lengths
Light-year (ly) - astronomical distance
Light-year is an astronomical distance equal to the distance light travels in vacuum in one Julian year. Used for interstellar and intergalactic scales; based on c = 299,792,458 m/s and a Julian year of 365.25 days (31,557,600 s)
- Symbol: ly
- System: Astronomical (non-SI, accepted for use with SI)
- Defined relation: 1 ly = c × 31,557,600 s = 9.4607304725808×10^15 m ≈ 9.4607×10^12 km
- Other relations: 1 ly ≈ 63,241.077 AU; 1 ly ≈ 0.306601 pc; 1 pc ≈ 3.26156 ly
- Typical examples: Proxima Centauri ~4.2465 ly; Milky Way diameter ~1.0×10^5 ly; Andromeda Galaxy ~2.5×10^6 ly