Wikipedia:WikiProject Aircraft/Units

There are plenty of converters to be found on-line, but if you want to do them manually, the conversion factors are:

Conversions

• Imperial to Metric
  • m = ((inches/12)+ft) / 3.28
  • m² = ft² / 10.76
  • kg = lb / 2.2
  • kW = hp × 0.746
  • kN = lb_f (thrust) / 224.26
  • km = miles × 1.61

• Metric to Imperial
  • ft = m × 3.28 (subtract the whole number from the result, then multiply the remainder by 12 to give the number of inches)
  • ft² = m² × 10.76
  • lb = kg × 2.2
  • hp = kW/0.746
  • lb_f (thrust) = kN × 224.26, or kg × 2.2 (if thrust is quoted in kg_f)
  • miles = km / 1.61

Overprecision for performance figures is unnecessary — most of these are approximates under specific conditions anyway, and many published figures show evidence of having already been converted between Imperial and metric and back again.

Don't have to worry about metric hp- 735.499 W and UK hp- 745.70 W

Thrust-to-weight ratio

• Non-metric units. Thrust units are called pounds. Weight units are also called pounds. The result can be expressed without showing the units.

• Metric units. Thrust units may be newtons (kN, MN etc). Weight will be kg. The result of dividing newtons by kilograms is N/kg (probably kN/kg).

• Of the various aircraft weights, the loaded weight is the one to be used on Wikipedia when calculating thrust to weight.