42.3 Millimeters to Inches

42.3 mm ≈ 1.6654 in

Closest fraction: 1 4364(1.67188 in — differs by less than 1%)

Calculation: in = 42.3 mm × 0.0393701 ≈ 1.6654 in

Millimeter to Inch Converter

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Sig. Figures:

How long is 42.3 mm?

42.3 mm (4.23 cm) is comparable to the width of a thumb or the diameter of a coin.

What does 42.3 mm look like?

Comparable to the width of a thumb or the diameter of a coin
42.3 mm (4.23 cm) is comparable to the width of a thumb or the diameter of a coin.

42.3 mm on the inch scale

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42.3 mm = 1.665 in

How to Convert Millimeter to Inch

1 millimeter = 0.0393701 inches exact

Inch = Millimeter × 0.0393701

Example: 42.3 mm × 0.0393701 = 1.6654 in

Reverse Conversion

To convert inches back to millimeters:

  • Remember, 1 inch equals 25.4 millimeters.
  • To convert 1.6654 in to mm, multiply 1.6654 x 25.4, resulting in 42.3 mm.

exact This conversion factor is exact by international definition.

42.3 mm is also equal to:

  • 4.23 centimeter
  • 0.0423 meter
  • 0.13878 feet
  • 0.04626 yard
About these units

Millimeter: Metric unit equal to one thousandth (1/1000) of a meter.

Inch: Imperial/US customary unit standardized as exactly 25.4 millimeters since 1959.

Frequently Asked Questions

How much is 42.3 millimeters in inches?

42.3 millimeters equals 1.6654 inches. This is calculated by multiplying 42.3 by the conversion factor 0.0393701.

What does 42.3 millimeters look like in inches?

42.3 millimeters (1.6654 inches) is one to four inches — a small component or connector.

How do you calculate 42.3 millimeters to inches?

Multiply 42.3 by the conversion factor 0.0393701. The calculation is 42.3 × 0.0393701 = 1.6654 inches. This factor is defined by international measurement standards.

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42.3 millimeters = 1.66535 inches
42.3 millimeters = 1.66535 inches — conversion chart

For general conversions between millimeters and inches, see the millimeters to inches converter.

Conversion factors verified against NIST, BIPM, ISO 80000-3 1 inch = 2.54 cm by international agreement (1959). Last reviewed: March 2026
Tiago Fernandes Reviewed by Tiago Fernandes

All unit conversions on CoolConversion use conversion factors defined or documented by internationally recognised standards bodies (such as ISO and NIST), including both SI and non-SI units.