Common Length Units
This converter supports commonly used units including:
- Meters (m)
- Kilometers (km)
- Centimeters (cm)
- Millimeters (mm)
- Inches (in)
- Feet (ft)
- Yards (yd)
- Miles (mi)
- Nautical miles (nmi)
How to Use the Length Converter
- Enter the value you want to convert.
- Select the unit you are converting from.
- Select the unit you want to convert to.
- View and copy the calculated result.
One meter equals exactly 100 centimeters, while one inch equals exactly 2.54 centimeters.
When to Convert Length Units
Length conversion is useful for travel, construction, engineering, mapping, science, surveying, fitness, and everyday measurements. An online converter helps reduce manual calculation errors and makes it easier to compare values expressed in different units.
Length Conversion FAQ
What is length?
Length tells us how long, tall, wide, or far something is. For example, we can measure the length of a pencil, the height of a person, or the distance between two cities.
What is the standard unit of length?
The meter, written with the symbol m, is the standard SI unit of length. Many other metric units are based on the meter.
How do I convert one length unit to another?
Multiply or divide by the correct conversion factor. For example, because 1 meter contains 100 centimeters, multiply meters by 100 to convert them to centimeters.
What is a conversion factor?
A conversion factor is a number that connects two units measuring the same quantity. For example, the conversion factor from inches to centimeters is 2.54 because 1 inch equals exactly 2.54 centimeters.
What is the difference between metric and imperial units?
The metric system includes millimeters, centimeters, meters, and kilometers and is based on powers of ten. Imperial and US customary measurements include inches, feet, yards, and miles.
How does the metric system work?
Metric units increase or decrease by powers of ten. One kilometer equals 1,000 meters, one meter equals 100 centimeters, and one centimeter equals 10 millimeters.
How can I check whether my conversion is reasonable?
Think about whether the target unit is larger or smaller than the original unit. When converting meters to centimeters, the number should increase because centimeters are smaller. When converting centimeters to meters, the number should decrease.
Why do some conversion answers contain many decimal places?
Some units do not divide evenly into other units. This can produce a long or repeating decimal. The result may be rounded to make it easier to read.
How many decimal places should I keep?
For ordinary schoolwork, follow the instructions in the question or round to the same level of precision as the original measurement. Scientific and engineering work may require more decimal places.
What is scientific notation, and why is it used in length conversions?
Scientific notation is a compact way to write very large or very small numbers. For example, one nanometer is written as 1 × 10−9 meters. It is useful when working with atomic distances or astronomical measurements.