A length converter moves a measurement between the metric (SI) and US/imperial systems — metres, kilometres and centimetres on one side; miles, yards, feet and inches on the other. It works by converting your value into a single base unit (metres) and back out to the unit you want. Because the international foot, yard, mile and inch are defined exactly in terms of the metre, these conversions aren't approximations — they're exact, and only rounded for display.
Reviewed: June 20, 2026 · Author: Naveen P N, Founder — AI Calculator · Verified against: the 1959 international yard-and-pound definitions, recomputed in code.
How the conversion works
Each unit has a fixed number of metres: a foot is 0.3048 m, a mile is 1609.344 m, and so on. To convert, multiply your value by the "from" unit's metres-per-unit to get metres, then divide by the "to" unit's metres-per-unit. That single base-unit pivot is why a converter can handle any pair of units with one simple rule instead of memorising dozens of direct factors.
Worked example — 1 mile in metric and imperial
Scenario: convert 1 mile to other length units.
One mile is exactly 1609.344 metres, which is 1.609344 km, 5280 feet or 1760 yards — all exact, by definition. Going the other way is just as clean: 100 metres is 328.084 feet, 5 km is 3.10686 miles, and 12 inches is exactly 1 foot (30.48 cm). The converter above does all of these and shows the value in every supported unit at once.
Frequently Asked Questions
3.28084 ft, since 1 ft = 0.3048 m exactly.
× 0.621371 (÷ 1.609344). 5 km = 3.10686 mi. Roughly 8 km ≈ 5 mi.
Exactly 2.54 cm (1 in = 25.4 mm). 12 in = 30.48 cm.
Yes — yard, foot, mile, inch are defined exactly in metres since 1959.
Exactly 1852 m (~1.15 statute miles), used in sea/air navigation.