Useful for road trips, routes, and longer distances.
1 km = 1,000 mCONVERTERS
Length Converter
Convert length and distance measurements between metric and US customary units. Compare meters, kilometers, centimeters, millimeters, miles, yards, feet, and inches in one place.
Convert length units
Convert metric and US customary measurements.
Quick examples
8 unitsCommon length measures
Fixed factorsConsistent unit relationships
Your conversion results will appear here
Enter a measurement, choose the source and destination units, then select Convert measurement.
01Enter a value
02Choose your units
03Compare equivalents
MEASUREMENT GUIDE
Convert length measurements with confidence
Length conversion is useful whenever a measurement is expressed in a unit different from the one you need. Use this converter for everyday distances, product dimensions, schoolwork, travel planning, DIY projects, and measurement comparisons.
How to use the Length Converter
- Enter the number you want to convert.
- Choose the original unit in the From menu.
- Choose the required unit in the To menu.
- Select Convert measurement to calculate.
- Review the result, equivalent values, and conversion table.
Use Swap units to reverse the direction. The calculator keeps your input value but clears the previous result, so you can check the reversed conversion by selecting Convert again.
How does length conversion work?
The converter uses the meter as a common reference unit. First, the input is converted to meters. That reference value is then divided by the number of meters represented by the destination unit.
Converted valueInput value × source unit in meters ÷ destination unit in meters
For example, one foot equals 0.3048 meters, while one inch equals 0.0254 meters. Converting 12 inches to feet means converting the input to meters and then dividing by the number of meters in one foot. The result is exactly 1 foot.
Common length conversion factors
These fixed relationships are useful for checking everyday measurements. The values shown as decimals are rounded for display unless the relationship is stated as exact.
| Conversion | Equivalent | Relationship |
|---|---|---|
| 1 kilometer | 1,000 meters | Exact |
| 1 meter | 100 centimeters | Exact |
| 1 centimeter | 10 millimeters | Exact |
| 1 inch | 2.54 centimeters | Exact |
| 1 foot | 12 inches | Exact |
| 1 yard | 3 feet | Exact |
| 1 mile | 5,280 feet | Exact |
| 1 mile | 1.609344 kilometers | Exact |
| 1 meter | 3.280839895 feet | Rounded display |
| 1 meter | 39.37007874 inches | Rounded display |
For authoritative background on measurement standards, see the NIST guide to SI units.
Metric units: meters, kilometers, centimeters, and millimeters
The metric system is organized around powers of ten. A kilometer contains 1,000 meters, a meter contains 100 centimeters, and a centimeter contains 10 millimeters. This makes conversions within the metric system straightforward: moving to a smaller unit increases the numerical value, while moving to a larger unit decreases it.
A common reference unit for everyday length.
1 m = 100 cmUseful for small objects and product dimensions.
1 cm = 10 mmUseful for fine measurements and small details.
1,000 mm = 1 mUS customary units: miles, yards, feet, and inches
Miles, yards, feet, and inches are common in US customary measurements. These units have fixed relationships, but they do not use the same powers-of-ten pattern as metric units. Remember that 12 inches make a foot, 3 feet make a yard, and 5,280 feet make a mile.
If you are working on a home project, a length conversion may be useful alongside the square-footage tool or flooring calculator. Length measures one dimension; area measures a two-dimensional surface, so the units are related but not interchangeable.
Worked length conversion examples
Meters to feet
Convert 5 meters to feet.
5 × 3.280839895 ≈ 16.4042 ft
Five meters is approximately 16.4042 feet.Miles to kilometers
Convert 10 miles to kilometers.
10 × 1.609344 = 16.09344 km
Ten miles equals 16.09344 kilometers.Inches to centimeters
Convert 12 inches to centimeters.
12 × 2.54 = 30.48 cm
Twelve inches equals exactly 30.48 centimeters.Why do converted values sometimes have decimals?
Some units divide evenly into others, while many conversions produce decimal values. For example, 12 inches equals exactly one foot, but one meter is approximately 3.28084 feet. Decimal results are normal and do not necessarily indicate a calculation error.
The converter formats results to make them readable. Display rounding does not change the underlying conversion factors. For construction, engineering, manufacturing, surveying, or other precision-sensitive work, follow the rounding and tolerance rules required for that task.
Length vs. distance: what is the difference?
Length commonly describes the size of an object or the measurement between two points. Distance often describes how far apart locations are or how far someone travels. Both can be expressed in meters, kilometers, feet, or miles, so the same unit relationships apply when converting their measurements.
Length conversion is different from converting area or volume. For example, converting square feet to square meters requires area-conversion factors, not ordinary length factors. For those tasks, try the area converter or volume converter. You can also use the speed converter when the measurement includes distance per unit of time.
Choosing the right precision
Use a level of precision that matches the purpose of your measurement. Everyday estimates may only need one or two decimal places, while technical tasks may require more. More decimal places do not automatically make a measurement more accurate if the original measurement itself is approximate.
- Everyday use: round to a practical, readable value.
- Schoolwork: follow the precision specified by the problem.
- Construction: follow project specifications and measurement tolerances.
- Technical work: retain sufficient precision for downstream calculations.
Frequently asked questions
How many feet are in one meter?
One meter is approximately 3.280839895 feet. The displayed result may be rounded for readability.
How many inches are in one foot?
One foot equals exactly 12 inches.
How many centimeters are in one inch?
One inch equals exactly 2.54 centimeters.
How many meters are in one kilometer?
One kilometer equals exactly 1,000 meters.
How many kilometers are in one mile?
One international mile equals exactly 1.609344 kilometers.
Can I convert a decimal or negative value?
Yes. The converter accepts finite decimal and negative numbers. Negative values are usually more relevant to signed displacement or coordinate calculations than to ordinary physical lengths.
Does the calculator round the result?
The calculator rounds displayed values for readability. Conversion calculations use the fixed factors defined for the supported units.
Are metric conversions always powers of ten?
Metric units such as kilometers, meters, centimeters, and millimeters are related by powers of ten. Conversions between metric and customary units use different fixed factors.
Can I use this converter for square feet or cubic feet?
No. Square units measure area and cubic units measure volume. Use an area or volume converter for those quantities instead of applying a length conversion factor.
Note: This tool converts numerical measurements using standard unit relationships. Always check required precision, tolerances, and project specifications when using converted values for technical or safety-sensitive work.