MM to Inches Converter

How to convert mm to inches

To convert millimeters to inches, divide the millimeter value by 25.4 (in = mm ÷ 25.4), because 1 inch equals exactly 25.4 millimeters.

Quick reference table

Millimeter (mm)Inch (in)
10.03937
50.19685
100.393701
250.984252
501.968504
1003.937008

Frequently Asked Questions

How many inches is an M6 bolt diameter?

An M6 bolt has a nominal 6 mm diameter, which is about 0.236 inches (6 ÷ 25.4 ≈ 0.236). That is why metric hardware can look close to a nearby imperial size without actually matching it.

Why convert 15 mm pipe or 8.3 mm phone thickness to inches?

Plumbing catalogs, US accessory specs, and mixed wrench sets often use inches. Converting 15 mm to about 0.591 inches and 8.3 mm to about 0.327 inches makes cross-market comparisons much easier.

More length conversions

Why use a real-time, two-way length converter?

Metric units like centimeters, meters and kilometers still coexist worldwide with imperial units like inches, feet, yards and miles. Whether you're checking furniture dimensions from an overseas store, converting a suitcase's inch spec, or comparing a child's height to international charts, mentally converting cm to inches or meters to feet is error-prone. This tool lets you pick a unit and type a value on either side — the other side updates instantly, no "calculate" button required.

Whenever you change a unit, the tool automatically saves your last-used pair to the browser's localStorage, so the next visit starts right where you left off.

Common length conversion factors

  • 1 centimeter (cm) = 10 millimeters (mm)
  • 1 meter (m) = 100 centimeters (cm)
  • 1 kilometer (km) = 1,000 meters (m)
  • 1 inch (in) = 2.54 centimeters (cm)
  • 1 foot (ft) = 12 inches (in) = 30.48 centimeters
  • 1 yard (yd) = 3 feet (ft) = 0.9144 meters
  • 1 mile = 1,760 yards (yd) = 1.609344 kilometers

Where metric and imperial units come from

The modern meter is defined by international agreement as part of the International System of Units (SI), while inches, feet, yards and miles belong to the imperial system, still widely used in the US and parts of the UK (home dimensions, height/weight, road distances). Knowing the exact ratios helps when shopping internationally, traveling abroad, or reading English technical specs.

Typical use cases

US-market monitors, furniture and clothing are often labeled in inches, while many other countries use centimeters and meters for room measurements and renovation planning; treadmill displays, maps and flight distances may mix miles and kilometers. Switch either side to any of the 8 supported units to cover everyday and professional conversion needs.

MM to Inches Converter

Use this direction when a caliper reading, technical drawing, or metric hardware label is in millimeters but the buyer, supplier, or spec sheet expects inches.

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