Unit Converter
Convert common length units instantly in your browser with a visible source and destination unit.
Convert common length units
Enter a value, choose the source unit, and choose the destination unit. The tool converts common length units such as millimeters, centimeters, meters, kilometers, inches, feet, yards, and miles. Keep the unit labels visible when copying a result into another document.
Conversion principle
Each unit has a factor relative to a common base unit. The converter multiplies the input by the source factor and divides by the destination factor. This approach keeps the direction clear and avoids silently treating a number as a different unit system.
Worked example
To convert 12 inches to feet, the source value is multiplied by the inch factor and divided by the foot factor, producing 1 foot. For a long distance, confirm whether the context expects statute miles, nautical miles, or another unit system.
Frequently asked questions
Frequently Asked Questions About Online Calculators
Does the converter require an account?
No. Common conversions run in the browser without signup.
Can I convert every unit?
No. The current page lists the supported units. Use the exact unit labels shown in the form.
Why is rounding different from another tool?
Different tools may display different decimal places. Compare the unrounded value and the unit definition before treating a small difference as an error.