What does 21 centimetres look like?

21-Centimetre Distance Comparisons

• Measured against the long side of a €100 note, 21 centimetres spans about 1.4 times that reference.

  The comparison uses the published dimension, converted into the same unit before the proportion is calculated.

  Source: European Central Bank

• Measured against the height of a table-tennis net, 21 centimetres spans about 1.4 times that reference.

  Its published measurement is 15.25 centimetres; the ratio is calculated from that figure.

  Source: International Table Tennis Federation

• For scale, 21 centimetres is about 50% of the long side of an A3 sheet.

  Using the source measurement of 42 centimetres, this comparison puts the target at 50% of it.

  Source: International Organization for Standardization

• Measured against the long edge of an ISO ID-1 payment card, 21 centimetres spans about 2.5 times that reference.

  The comparison uses the published dimension, converted into the same unit before the proportion is calculated.

  Source: International Organization for Standardization

• For scale, 21 centimetres is about 14% of the height of a badminton net at centre.

  The comparison uses the published dimension, converted into the same unit before the proportion is calculated.

  Source: Badminton World Federation

• 21 centimetres is about 14% of the width of a table-tennis table.

  Its published measurement is 152.5 centimetres; the ratio is calculated from that figure.

  Source: International Table Tennis Federation

• 21 centimetres is about 8.2 times the diameter of a 2-euro coin.

  Using the source measurement of 2.57 centimetres, this comparison puts the target at 8.2 of it.

  Source: European Commission

• 21 centimetres is approximately 8.3 inches.

  Using the exact conversion that 1 centimetre equals exactly 0.3937007874 inches, the unrounded result is 8.268 inches.