Length Converter
Convert millimeters, centimeters, meters, kilometers, inches, feet, yards, miles, and nautical miles.
Measurement converter
Unit Converter
Convert common measurement units instantly. Choose a category, enter a value, select your from and to units, and get a clear result with the conversion formula.
Free Browser-only No sign-up Instant formula
US and Imperial volume units are different. Make sure you select the correct gallon, pint, or fluid ounce.
Length
Enter a number to convert.
Formula Formula appears here.
Calculation Calculation appears here.
Precision Auto
Convert Units Online
Use this free unit converter to convert common measurement units instantly. You can convert length, mass, area, volume, speed, pressure, energy, temperature, and common SI/CGS units directly in your browser.
This converter uses standard conversion factors for common SI, metric, imperial, and US customary units. Some units, such as US gallons and Imperial gallons, are different, so always choose the exact unit you need.
Popular Unit Conversions
Open a dedicated converter page or use the calculator above.
Weight and Mass Converter
Convert milligrams, grams, kilograms, metric tons, ounces, pounds, and stones. Pound is treated as pound-mass.
Area Converter
Convert square metric units, square inches, square feet, square yards, acres, and hectares.
Volume Converter
Convert milliliters, liters, cubic units, US fluid ounces, cups, pints, quarts, US gallons, and Imperial gallons.
Speed Converter
Convert meters per second, kilometers per hour, miles per hour, feet per second, and knots.
Pressure Converter
Convert pascals, kilopascals, megapascals, bar, atmosphere, psi, torr, mmHg, and barye.
Energy Converter
Convert joules, kilojoules, calories, kilocalories, watt-hours, kilowatt-hours, BTU, electronvolts, and ergs.
SI and CGS Unit Conversion
Convert common mechanical SI/CGS pairs only. Electromagnetic CGS conversions are excluded because they are not simple one-to-one conversions.
How to Use the Unit Converter
- 1 Enter a number, including decimals or scientific notation like 1e6.
- 2 Choose a unit category, then select the from and to units.
- 3 Read the result, formula, and calculation. Adjust precision if needed.
- 4 Copy the result, swap units, reset the form, or use popular conversion shortcuts.
Unit Conversion Formulas
Most categories use a standard base-unit formula: base value = input × source factor, then result = base value ÷ target factor. Temperature uses dedicated Celsius, Fahrenheit, and Kelvin formulas.
CM to Inches Formula
inches = centimeters ÷ 2.54
KG to LBS Formula
pounds = kilograms × 2.2046226218
Pounds to Kilograms Formula
kilograms = pounds × 0.45359237
Liters to Gallons Formula
US gallons = liters × 0.2641720524
Joules to Calories Formula
calories = joules ÷ 4.184
Pascals to PSI Formula
psi = pascals × 0.0001450377
Unit Converter Chart
| Example | Result |
|---|---|
| 1 cm | 0.3937007874 in |
| 1 kg | 2.2046226218 lb |
| 1 L | 0.2641720524 US gal |
| 0 °C | 32 °F |
Frequently Asked Questions
What is a unit converter?
A unit converter changes a measurement from one unit to another, such as centimeters to inches, kilograms to pounds, or joules to calories.
How do I convert cm to inches?
To convert centimeters to inches, divide the centimeter value by 2.54. For example, 10 cm equals 3.937007874 inches.
How do I convert kg to lbs?
To convert kilograms to pounds, multiply kilograms by 2.2046226218. For example, 10 kg equals 22.046226218 lb.
Is pound a mass or weight unit?
In everyday search terms, users say weight, but in scientific conversion the pound here means pound-mass. The converter labels the category as Mass / Weight for clarity.
Does this tool support SI and CGS units?
Yes. It supports common mechanical SI/CGS conversions such as meter to centimeter, kilogram to gram, newton to dyne, joule to erg, pascal to barye, and m/s² to Gal.
Why are US gallons and Imperial gallons different?
US and Imperial measurement systems define gallons differently. Select US gallon or Imperial gallon carefully before converting.
Is this unit converter private?
Yes. The calculation runs in your browser and does not need a server request. Recent conversions, if enabled, are stored only in your browser.
Can I use this converter on mobile?
Yes. The tool supports mobile numeric keyboards, large tap targets, responsive layout, and keyboard-accessible controls.