ThisCalculator

Conversions

Inches to Centimetres Calculator

Updated · Standard formula, shown below

Centimetres 69.85 cm
Millimetres
698.5 mm
Result
Feet
2.292 ft
Result
Metres
0.6985 m
Result

This calculator converts a length in inches to centimetres, and also shows millimetres, feet and metres. Enter the length in inches, including decimals for fractions of an inch.

Formula

Centimetres = inches × 2.54 (exact, by international definition since 1959). Millimetres = inches × 25.4. Feet = inches ÷ 12. Metres = inches × 0.0254.

  • x: length in inches

Worked Example

27.5 inches.

  1. 27.5 × 2.54 = 69.85 cm
  2. 27.5 × 25.4 = 698.5 mm
  3. 27.5 ÷ 12 = 2.292 ft
  4. 27.5 × 0.0254 = 0.6985 m

Limits and common mistakes

  • Fractions must be decimals: 3/8 in = 0.375, 1/16 in = 0.0625.
  • To go back, divide centimetres by 2.54.
  • Rounding: the factor is exact, so any error comes only from rounding the result for display.
  • Tape measures marked in fractions: 27 1/2 in is 27.5 in, 27 5/8 in is 27.625 in.
  • Feet and inches together: multiply the feet by 12 and add the inches before converting (5 ft 7 in = 67 in = 170.18 cm).
  • Screen sizes are diagonal inches; a 27.5 in diagonal is 69.85 cm diagonal, not the width.
Formula used
in x | Length | in | 27.5 | 0
out cm | Centimetres | cm | x * 2.54 | 2
out mm | Millimetres | mm | x * 25.4 | 1
out ft | Feet | ft | x / 12 | 3
out m | Metres | m | x * 0.0254 | 4

Each line is one input (in, sel, list) or one result (out: label, unit, formula, decimals). How the calculators work

Method: the standard formula for this calculation, rounded as each result states. See how the calculators work or report an error.