21 inches

TV & monitor size

17.81 x 11.13 in

Aspect ratio 4:3

Aspect ratio 5:4

Aspect ratio 16:9

Aspect ratio 16:10

Aspect ratio 21:9

Aspect ratio 32:9

Metric

  • Kilometre (km)
    4.52×10⁻⁴ x 2.83×10⁻⁴
  • Metre (m)
    0.45 x 0.28
  • Decimetre (dm)
    4.52 x 2.83
  • Centimetre (cm)
    45.23 x 28.27
  • Millimetre (mm)
    452.32 x 282.7
  • Micrometre (µm)
    452,322.3 x 282,701.43
  • Nanometre (nm)
    452,322,295.36 x 282,701,434.6
  • Angstrom (Å)
    4.52×10⁹ x 2.83×10⁹

British/American

  • League
    9.37×10⁻⁵ x 5.86×10⁻⁵
  • Mile (mi)
    2.81×10⁻⁴ x 1.76×10⁻⁴
  • Furlong
    2.25×10⁻³ x 1.41×10⁻³
  • Chain
    0.02 x 0.01
  • Rod (rd)
    0.09 x 0.06
  • Yard (yd)
    0.49 x 0.31
  • Foot (ft)
    1.48 x 0.93
  • Link
    2.25 x 1.41
  • Hand
    4.45 x 2.78
  • Inch (in)
    17.81 x 11.13
  • Line
    178.08 x 111.3
  • Mil (mil)
    17,807.96 x 11,129.98
  • Thou (thou)
    17,807.96 x 11,129.98

Nautical

  • Nautical mile
    2.44×10⁻⁴ x 1.53×10⁻⁴
  • Fathom
    0.25 x 0.15

Astronomical

  • Parsec (pc)
    1.47×10⁻¹⁷ x 9.16×10⁻¹⁸
  • Light year
    4.78×10⁻¹⁷ x 2.99×10⁻¹⁷
  • Astronomical unit (AE)
    3.02×10⁻¹² x 1.89×10⁻¹²
  • Light minute
    2.51×10⁻¹¹ x 1.57×10⁻¹¹
  • Light second
    1.51×10⁻⁹ x 9.43×10⁻¹⁰