Free online length converter. Convert inches to centimeters, feet to meters, miles to kilometers, yards, millimeters, and more — instant results, strong validation, visual comparison chart.
Metric • Imperial • 10 units
Uses exact conversion factors from the National Institute of Standards and Technology — 1 inch = 2.54 cm exactly.
See the scale difference at a glance — helpful when converting very large or very small measurements.
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The United States uses a unique mix of imperial and customary units for length while most of the world uses the metric system. This creates constant conversion needs for Americans shopping internationally, reading foreign product specs, calculating running distances, understanding European maps, or communicating height and dimensions with overseas contacts.
The most commonly searched length conversions in the USA: Inches to centimeters (1 in = 2.54 cm exactly) — used for screen sizes, TV dimensions, phone specs, and furniture. Feet to meters (1 ft = 0.3048 m) — used for height, room dimensions, and construction. Miles to kilometers (1 mile = 1.60934 km) — used for international driving distances and running/cycling events. Centimeters to inches — the reverse of the above, used when reading foreign specs in metric and converting to a familiar US measurement.
Quick mental shortcuts: For cm to inches, divide by 2.5 (close enough for everyday use — exact is ÷2.54). For km to miles, multiply by 0.6 (exact is 0.621371). For meters to feet, multiply by 3.28. A person who is 6 feet tall is 182.88 cm (about 183 cm). A 100-meter sprint is approximately 328 feet or 109 yards — slightly longer than an American football field (100 yards = 91.44 m).
TV and monitor sizes are listed diagonally in inches in the US. 55" = 139.7 cm. 65" = 165.1 cm. 75" = 190.5 cm. 85" = 215.9 cm. Phone screens: 6.1" = 15.5 cm. 6.7" = 17 cm.
5K = 3.107 miles. 10K = 6.214 miles. Half marathon = 13.109 miles = 21.097 km. Full marathon = 26.219 miles = 42.195 km. 1 mile = 5,280 feet = 1,760 yards = 1.609 km.
Standard US ceiling height: 8 ft = 2.44 m. 9 ft = 2.74 m. King bed: 76" × 80" = 193 × 203 cm. Standard doorway: 80" tall = 6'8" = 203 cm. 2×4 lumber is actually 1.5" × 3.5" = 3.8 × 8.9 cm.
US interstate speed limit 65 mph = 104.6 km/h. 70 mph = 112.7 km/h. NYC to LA = 2,790 miles = 4,491 km. NY to London = 3,459 miles = 5,567 km. Earth circumference = 24,901 miles = 40,075 km.