Length & Distance Converter
This converter uses exact defined relationships between customary and metric units, including 1 in = 2.54 cm and 1 mi = 1,609.344 m, and is reviewed for calculation accuracy and clarity. Results are rounded for display where appropriate.
Convert between miles, kilometers, meters, yards, feet, inches, centimeters, and millimeters in any direction. Enter a value, choose the source and target unit, and the tool returns the converted result, the same distance in every supported unit, the exact conversion factor, the substituted equation, and a reference table for common distances.
Example result shown below. Edit the fields above and it recalculates instantly.
How It Works
Length conversions are purely proportional: each unit is a fixed multiple of the meter, so a conversion is one multiplication by an exact factor. The customary units are defined exactly in metric terms — an inch is exactly 2.54 cm, a foot is exactly 0.3048 m, and a mile is exactly 1,609.344 m — so nothing here is an approximation except the rounding in the display.
Metric units scale by powers of ten (1 km = 1,000 m = 100,000 cm). The customary units chain from the inch: 12 inches to a foot, 3 feet to a yard, 1,760 yards to a mile.
Worked Examples
Miles to kilometers: 1 mi ≈ 1.609344 km; a 26.2-mile marathon ≈ 42.195 km.
Kilometers to miles: 1 km ≈ 0.621371 mi; a 5 km run ≈ 3.10686 mi.
Feet and centimeters: 6 ft = 182.88 cm; 100 cm ≈ 3.28084 ft.
Inches: 1 in = 2.54 cm exactly; 12 in = 1 ft = 30.48 cm.
What This Result Means
The headline is your direct conversion; the "All units" table shows the same distance across every supported unit at once, which is useful when a measurement is quoted in one unit and you need another. Every factor is exact by definition, so the only source of imprecision is display rounding.
When to Use This Calculator
Use it for travel distances between metric and customary countries, running and cycling distances, height, construction and DIY measurements, screen and print dimensions, and any spec that mixes inches, feet, meters, or centimeters.
Limitations
- Negative distance is not meaningful, so negative inputs are rejected with a clear message.
- Results are displayed to a sensible precision while exact factors (1 mi = 1,609.344 m, 1 in = 2.54 cm) are used internally.
- This converts length only; it does not handle area or volume units.
Frequently Asked Questions
How many kilometers are in a mile?
Exactly 1.609344 kilometers. Going the other way, one kilometer is about 0.621371 miles.
How many centimeters in an inch?
Exactly 2.54 centimeters — the inch is defined in metric terms, so this is not an approximation.
How do I convert my height from feet to centimeters?
Multiply feet by 30.48. For example, 6 ft = 6 × 30.48 = 182.88 cm. Add any extra inches × 2.54.
What is a 5K in miles?
A 5-kilometer distance is about 3.10686 miles. A 10K is about 6.21371 miles.