FREETY.TOOLS

Frequently asked questions (FAQs)

• How is the conversion calculated?

  The conversion uses square meters (m²) as the base unit, with predefined m² values for each unit.
  The formula is as follows:
  Result = Input × (m² value of source unit) ÷ (m² value of target unit)

• Are Imperial and US area units different?

  Area units are practically the same.
  The definitions for inch, foot, yard, and acre are identical, so conversion results are the same.
  (Volume and weight differ, so keep those categories separate.)

• Are 'pyeong', 'danbo', and 'jeongbo' accurate?

  They follow Korean customary standards.
  
  1 Pyeong = 3.305785 m²
  1 Danbo = 300 Pyeong = 991.7355 m²
  1 Jeongbo = 3,000 Pyeong = 9,917.355 m²
  These are widely used standard values, but displayed results may vary slightly depending on decimal precision settings.

• How is rounding handled?

  Calculations use exact definitions (e.g., 1 ft = 0.3048 m, 1 in = 0.0254 m), and rounding is applied only at the display stage.

• What happens if the input or output unit is selected incorrectly?

  Units are restricted to predefined keys, and invalid selections are blocked.
  Example: square_meter, square_foot, pyeong, etc.
  If an unknown key is provided, an error message will appear: “Unsupported unit.”

• What about zero, negative, or very large values?

  Zero: The result is always zero.
  Negative: Mathematically possible, but usually meaningless for physical area, so a warning is recommended.
  Very large values: Overflow is unlikely, but the UI should limit excessive decimal places and suggest appropriate units (e.g., km² instead of m²) for extremely large inputs.

• Can rounding errors occur?

  Minor differences may occur depending on displayed precision.
  Example: 1 acre ≈ 4,046.8564224 m²; when converting to pyeong, rounding may cause ±1–2 pyeong variation.
  For high-precision tasks, keep maximum precision internally and apply appropriate rounding for display.

• Why use m² as the base unit?

  m² is the standard SI area unit, and most conversion definitions are based on meters, ensuring minimal error and better scalability.

• What is the level of precision?

  International definitions (inch, foot, yard, acre) use exact SI-based values (e.g., 1 in = 25.4 mm).
  Korean customary units (pyeong, danbo, jeongbo) use standard accepted values, but minor display variations may occur depending on decimal settings.

• What are the sources of unit definitions?

  International standards and Korean customary values are used.
  
  International: SI definitions (1 inch = 25.4 mm, 1 foot = 0.3048 m, 1 yard = 0.9144 m, 1 acre = 43,560 ft²)
  Korean customary: Commonly used conversion standards (pyeong = 3.305785 m²)