Convert Any Unit,Instantly
Free, fast, and accurate online unit converter. Convert between hundreds of units across 15+ categories including length, weight, temperature, and more.
All Unit Categories
Choose from 15 categories covering every type of measurement conversion you need.
Length
Convert between length and distance units including meters, feet, inches, kilometers, miles, and more.
20 converters →Weight
Convert between weight and mass units including kilograms, pounds, ounces, grams, tons, and more.
16 converters →Temperature
Convert between temperature units including Celsius, Fahrenheit, and Kelvin.
6 converters →Area
Convert between area units including square meters, square feet, acres, hectares, square kilometers, and more.
14 converters →Volume
Convert between volume units including liters, gallons, cups, milliliters, cubic meters, and more.
18 converters →Speed
Convert between speed units including meters per second, kilometers per hour, miles per hour, knots, and Mach.
10 converters →Time
Convert between time units including seconds, minutes, hours, days, weeks, months, and years.
14 converters →Digital Storage
Convert between digital storage units including bits, bytes, kilobytes, megabytes, gigabytes, terabytes, and petabytes.
12 converters →Pressure
Convert between pressure units including pascals, bar, PSI, atmospheres, mmHg, and torr.
10 converters →Energy
Convert between energy units including joules, calories, kilowatt hours, BTU, electronvolts, and more.
14 converters →Frequency
Convert between frequency units including hertz, kilohertz, megahertz, and gigahertz.
6 converters →Fuel Economy
Convert between fuel economy units including miles per gallon, kilometers per liter, and liters per 100 kilometers.
6 converters →Power
Convert between power units including watts, kilowatts, horsepower, and BTU per hour.
8 converters →Angle
Convert between angle units including degrees, radians, and gradians.
6 converters →Data Transfer Rate
Convert between data transfer rate units including bits per second, kilobits, megabits, and gigabits per second.
8 converters →Most Popular Conversions
Quick access to the most commonly used unit conversions.
Celsius to Fahrenheit
Temperature
Kilograms to Pounds
Weight
Meters to Feet
Length
Kilometers to Miles
Length
Liters to US Gallons
Volume
Miles to Kilometers
Length
Fahrenheit to Celsius
Temperature
Pounds to Kilograms
Weight
Inches to Centimeters
Length
Miles per Hour to Kilometers per Hour
Speed
US Gallons to Liters
Volume
Feet to Meters
Length
Why Use UnitConverterOnlines?
Everything you need for quick, accurate unit conversions in one place.
Accurate Results
All conversions use precise, verified conversion factors sourced from international standards.
Instant Conversion
Results appear instantly as you type. No waiting, no page reloads needed.
15+ Categories
From length and weight to digital storage and data transfer rates. Every unit you need.
Works on All Devices
Fully responsive design that works perfectly on desktop, tablet, and mobile devices.
100% Free
No sign-up required, no hidden costs. All conversion tools are completely free to use.
Educational Content
Each converter includes formulas, examples, and detailed explanations to help you learn.
How It Works
Converting units is simple with our tool.
Select Category
Choose from 15+ unit categories like length, weight, or temperature.
Choose Units
Select the units you want to convert from and to.
Enter Value
Type your value and get instant, accurate results.