What Is a Unit Converter?
A unit converter is a tool that converts a measurement from one unit to another while keeping the same value and meaning. Common examples include converting kilometers to miles, kilograms to pounds, liters to gallons, or Celsius to Fahrenheit. Unit converters support different measurement categories such as length, weight, temperature, area, volume, speed, time, pressure, energy, and more.
Our unit converter provides real-time results as you enter a value, with formula display and precision control to help you understand and adjust each conversion.
14 Categories
Length, weight, temperature, area, volume, speed, time, data storage, pressure, energy, force, power, angle, and data transfer
75+ Units
Comprehensive library covering 75+ measurement units across metric, imperial, and other commonly used systems.
Real-Time
Results update instantly as you type, so you can convert values without submitting a form or reloading the page.
350+ Conversions
Over 350 possible conversion pairs across all supported categories.
How to Use the Unit Converter in 3 Easy Steps
Using our unit converter is quick and easy. Follow these three simple steps to convert measurements between units and get an accurate result instantly.
Select a Category
Choose the type of measurement you want to convert, such as length, weight, temperature, volume, speed, or time.
Choose Units
Select the unit you are converting from and the unit you want to convert to. Use the swap option to quickly reverse the conversion direction when available.
Enter Value
Enter the value you want to convert. The converter calculates the result instantly and displays the conversion formula used for the calculation.
Unit Conversion Categories
Our unit converter currently supports 14 measurement categories, with multiple units available within each category. Choose a category below to convert between commonly used metric, imperial, and scientific units.
Length
Millimeters, centimeters, meters, kilometers, inches, feet, yards, miles, and more.
Weight / Mass
Milligrams, grams, kilograms, tonnes, ounces, pounds, stones, and more.
Temperature
Celsius, Fahrenheit, Kelvin, Rankine, and other temperature scales.
Area
Square meters, square feet, acres, hectares, square miles, and more.
Volume
Milliliters, liters, gallons, quarts, pints, cups, fluid ounces, and more.
Speed
Meters per second, kilometers per hour, miles per hour, knots, and more.
Time
Milliseconds, seconds, minutes, hours, days, weeks, months, years, and more.
Data Storage
Bytes, kilobytes, megabytes, gigabytes, terabytes, and more.
Pressure
Pascals, bars, PSI, atmospheres, torr, and more.
Energy
Joules, calories, kilocalories, watt-hours, kilowatt-hours, and more.
Force
Newtons, kilonewtons, pound-force, kilogram-force, and more.
Power
Watts, kilowatts, megawatts, horsepower, and more.
Angle
Degrees, radians, gradians, arcminutes, arcseconds, and more.
Data Transfer
Bits per second, kilobits, megabits, and gigabits per second, and more.
Popular Unit Conversions
Below are some of the most commonly used unit conversions across length, weight, temperature, volume, speed, and data storage. Use the formulas as a quick reference, or enter your value in the unit converter above for an instant result.
Length Conversions
| Conversion | Formula / Relationship |
|---|---|
| Kilometers to Miles | mi = km × 0.621371 |
| Miles to Kilometers | km = mi × 1.60934 |
| Meters to Feet | ft = m × 3.28084 |
| Feet to Meters | m = ft × 0.3048 |
| Inches to Centimeters | cm = in × 2.54 |
| Centimeters to Inches | in = cm × 0.393701 |
Weight Conversions
| Conversion | Formula / Relationship |
|---|---|
| Kilograms to Pounds | lb = kg × 2.20462 |
| Pounds to Kilograms | kg = lb × 0.453592 |
| Grams to Ounces | oz = g × 0.035274 |
| Ounces to Grams | g = oz × 28.3495 |
Temperature Conversions
| Conversion | Formula / Relationship |
|---|---|
| Celsius to Fahrenheit | °F = (°C × 9/5) + 32 |
| Fahrenheit to Celsius | °C = (°F − 32) × 5/9 |
| Celsius to Kelvin | K = °C + 273.15 |
Volume Conversions
| Conversion | Formula / Relationship |
|---|---|
| Liters to Gallons (US) | gal = L × 0.264172 |
| Gallons (US) to Liters | L = gal × 3.78541 |
| Milliliters to Liters | L = mL ÷ 1000 |
Speed Conversions
| Conversion | Formula / Relationship |
|---|---|
| Kilometers per Hour to Miles per Hour | mph = km/h × 0.621371 |
| Miles per Hour to Kilometers per Hour | km/h = mph × 1.60934 |
Data Storage Conversions
| Conversion | Formula / Relationship |
|---|---|
| Megabytes to Gigabytes | GB = MB ÷ 1024 |
| Gigabytes to Megabytes | MB = GB × 1024 |
| Gigabytes to Terabytes | TB = GB ÷ 1024 |
How Does Unit Conversion Work?
Unit conversion changes a measurement from one unit to another while representing the same physical quantity. For example, kilometers and miles both measure distance, while kilograms and pounds measure mass, and Celsius and Fahrenheit measure temperature.
Converting between units uses a defined conversion factor that relates one unit to another. For example, one mile equals 1.60934 kilometers, so a distance in miles can be converted to kilometers by multiplying by that conversion factor.
Our unit converter automatically applies the correct conversion factor for the selected units, so you only need to choose the units and enter a value to get the converted result.
Common Conversions Explained
The following examples explain some of the most commonly searched unit conversions, including the formula used and a practical example.
Kilometers to Miles
Kilometers and miles both measure distance. Kilometers are part of the metric system, while miles are primarily used in the United States and the United Kingdom.
How to convert: To convert kilometers to miles, multiply the number of kilometers by 0.621371.
Formula
miles = kilometers × 0.621371Example
10 km × 0.621371 = 6.21371 milesKilograms to Pounds
Kilograms and pounds both measure mass. Kilograms are used in the metric system, while pounds are commonly used in the imperial system.
How to convert: To convert kilograms to pounds, multiply the number of kilograms by 2.20462.
Formula
pounds = kilograms × 2.20462Example
5 kg × 2.20462 = 11.0231 poundsCelsius to Fahrenheit
Celsius and Fahrenheit are two different temperature scales. Celsius is used in most countries, while Fahrenheit is primarily used in the United States.
How to convert: To convert Celsius to Fahrenheit, multiply the Celsius temperature by 9/5 and then add 32.
Formula
°F = (°C × 9/5) + 32Example
25°C × 9/5 + 32 = 77°FWhy Use Our Unit Converter?
Whether you're a student, engineer, traveler, or professional, our unit converter provides accurate, real-time conversions across 14 categories, with 75+ units and 350+ conversion pairs.
Completely Free
No limits, hidden fees, or registration required.
Privacy Focused
Conversions run in your browser, so your conversion values do not need to be sent to a server.
14 Categories
Convert measurements across length, weight, temperature, volume, speed, time, and many other categories.
Precision Control
Choose from 0–6 decimal places or display the full calculated value.
Popular Conversions
Quick access to commonly used conversions for faster results.
Formula Display
See the formula used to calculate each result so you can understand how the conversion was made.
Accuracy and Precision
Our unit converter uses standard conversion factors and performs calculations at full internal precision. You can choose how many decimal places to display, from 0 to 6 decimal places or full precision.
Displayed precision and mathematical accuracy are not the same thing. Rounding only changes how the result is displayed; it does not change the underlying calculation.
For high-consequence work in engineering, science, medicine, or finance, we recommend independently verifying critical results against a trusted source or reference.
Is This Unit Converter Safe?
100% SECUREConversions are performed in your browser, and the values you enter are not sent to our servers for calculation.
Recent conversions may be kept in your browser so you can quickly reference them during your session. You can clear this history at any time using the Clear option in the Conversion History section.
Common Uses for a Unit Converter
Our unit converter is useful for students, engineers, travelers, cooks, scientists, and professionals who need to convert measurements between different units quickly and easily.
💡Tips for Accurate Unit Conversion
- ✓Make sure both units measure the same physical quantity. For example, you cannot directly convert a unit of weight to a unit of length.
- ✓Double-check that you have selected the correct units, especially when similar units or different measurement systems are available.
- ✓Use higher precision only when it is needed. More decimal places are not always more useful.
- ✓For engineering, scientific, medical, or financial work, verify critical calculations against an independent reference.
- ✓Remember that displayed values may be rounded according to your selected precision, while the underlying calculation retains full precision.
- ✓Review the displayed formula to understand how the result was calculated.
- ✓Use the swap button to quickly reverse the From and To units.
- ✓At very high precision, small differences may appear due to floating-point arithmetic.