Length/Distance Converter
Convert between meters, kilometers, miles, feet, inches, yards, nautical miles, and light years with precision.
Enter the distance to convert
Select source unit
Select target units (multiple selection possible)
Adjust the number of decimal places in results
Conversion Results
100 m = 0.1 km
Online Length & Distance Converter
Online Length & Distance Converter
Looking for a reliable length or distance converter? ModernConvert’s free tool lets you convert between meters, kilometers, miles, feet, inches, yards, nautical miles, and light years with scientific-grade precision.
Choose your measurement system, enter a value, and get instant conversions in all the units you need — ideal for everyday measurements, engineering, travel, and even astronomy.
How to Use the Length/Distance Converter
- 1. Select a measurement system
Choose between Metric, Imperial, Nautical/Aviation, Astronomical, or All Systems to focus only on the units you care about.
2. Enter the input value
Type the distance you want to convert in the Input Value field (for example,
100,3.5, or0.001).3. Pick your source unit
● Meters (m)
● Kilometers (km)
● Miles (mi)
● Feet (ft)
● Inches (in)
● Yards (yd)
● Nautical Miles (nmi)
● Light Years (ly)
Select the starting unit, such as:4. Choose one or more target units
You can convert to a single unit or multiple units at once (for example, meters → kilometers, miles, and feet in one click).
5. Set decimal precision (optional)
Adjust the Decimal Places setting to control how many digits appear after the decimal point for more exact or more readable results.
6. View, copy, and reset results
● See all conversion results in the Conversion Results panel
● Use Copy result to quickly copy values
● Use Reset All to clear the form or Swap Units to reverse the conversion direction.
- Supported Length & Distance Units
ModernConvert’s length or distance converter covers the most important systems and units:
● Metric: meters (m), kilometers (km)
● Imperial/US: inches (in), feet (ft), yards (yd), miles (mi)
● Nautical/Aviation: nautical miles (nmi)
● Astronomical: light years (ly)
Key relationships used in the calculator include:
1 kilometer = 0.621371 miles (approx.)
1 mile = 1.60934 kilometers (approx.)
1 meter = 3.28084 feet (approx.)
1 nautical mile = 1.852 kilometers
1 light year ≈ 9.46 trillion kilometers (5.88 trillion miles)
These standard conversion factors match widely accepted scientific and engineering values.
Quick Length & Distance Shortcuts
For common real-world distances, use the Quick Conversions built into the page:
● 1 km → miles
● 1 mile → km
● Marathon (42.2 km)
● Earth circumference
● 1 light year → km
● Average distance to the Moon
● Football field length
● Nautical mile → km
These shortcuts help you understand scale — from running distances and sports fields to planetary and interstellar distances.
Why Use ModernConvert’s Length/Distance Converter?
✅ All major units in one place – Metric, imperial, nautical, and astronomical units in a single tool
✅ Scientific-grade calculations – Designed for precise, repeatable results with adjustable decimal places
✅ Multi-unit output – Convert one value into several units at once
✅ Quick reference section – Built-in Length & Distance Reference with definitions, examples, and key relationships
✅ Free and instant – No login or subscription required
Whether you’re converting feet to meters, miles to kilometers, nautical miles to kilometers, or even light years to kilometers, this tool is built to handle everyday and advanced length conversions.
Length & Distance Reference (At a Glance)
Use this section as a quick learning hub while you convert:
Everyday distances: centimeters, meters, kilometers, feet, yards, miles
Navigation distances: nautical miles for marine and aviation routes
Space distances: light years to grasp extremely large scales used in astronomy
For example, a light year is the distance light travels in one year — about 9.46 trillion kilometers or 5.88 trillion miles.
FAQs: Length or Distance Converter
What is a length or distance converter?
A length or distance converter is an online calculator that converts a distance from one unit (like meters) into another (like feet, miles, or kilometers). ModernConvert’s tool supports metric, imperial, nautical, and astronomical units in a single interface.
Which units can I convert on ModernConvert?
You can convert between meters, kilometers, miles, feet, inches, yards, nautical miles, and light years, with options to show only metric, imperial, nautical/aviation, astronomical, or all systems.
How accurate are the conversions?
The tool uses standard, widely accepted conversion factors (for example, 1 mile ≈ 1.60934 km and 1 km ≈ 0.621371 miles) and lets you choose the number of decimal places for your results, making it suitable for both everyday and technical use.
Can I convert to more than one unit at once?
Yes. After choosing your source unit, you can select multiple target units so that one input value is converted into several units simultaneously, which is useful for comparison and learning.
What’s the difference between nautical miles and regular miles?
A nautical mile is used mainly in marine and air navigation and is defined as 1.852 kilometers, while a regular (statute) mile is about 1.609 kilometers. Nautical miles are tied to the Earth’s geometry and work well with knots (nautical miles per hour).
Why does this converter include light years?
Light years are a unit of distance used in astronomy to describe how far light travels in one year. Including light years in the converter helps users compare vast cosmic scales with more familiar units like kilometers or miles.