Free Unit Converters
Convert length, weight, temperature, speed, area, volume, data size, currency, and number bases — instantly.
Number Base Converter
Convert numbers between binary, octal, decimal, and hex.
Roman Numeral Converter
Convert numbers to Roman numerals and back.
Temperature Converter
Convert between Celsius, Fahrenheit, and Kelvin.
Data Size Converter
Convert between bytes, KB, MB, GB, and TB.
Length Converter
Convert between mm, cm, m, km, inches, feet, and miles.
Weight Converter
Convert between grams, kilograms, pounds, and ounces.
Area Converter
Convert between m², ft², acres, and hectares.
Volume Converter
Convert between liters, gallons, cups, and more.
Speed Converter
Convert between mph, km/h, m/s, and knots.
Time Converter
Convert between seconds, minutes, hours, days, and years.
Pressure Converter
Convert between Pa, bar, psi, atm, and mmHg.
Energy Converter
Convert between joules, calories, kWh, and BTU.
Power Converter
Convert between watts, kilowatts, and horsepower.
Frequency Converter
Convert between Hz, kHz, MHz, GHz, and RPM.
Angle Converter
Convert between degrees, radians, and gradians.
Force Converter
Convert between newtons, pound-force, and kgf.
Torque Converter
Convert between N·m, lb·ft, and lb·in.
Data Transfer Rate Converter
Convert between Mbps, MB/s, Gbps, and more.
Fuel Economy Converter
Convert between MPG, km/L, and L/100km.
Currency Converter
Convert currencies with live exchange rates.
Number to Words Converter
Spell out any number in English words.
Conversion Calculator
One converter for every unit.
About these unit converters
Fast, accurate unit converters for every measurement you look up — length (cm to inches, feet to meters), weight (kg to lbs), temperature (Celsius to Fahrenheit), speed (mph to km/h), area, volume (ml to oz, liters to gallons), data size, energy, power, pressure, fuel economy, number bases, and live currency exchange rates. Type a value once and see every unit at the same time — no sign-up, no ads blocking the result, just instant conversions for cooking, travel, school, and work.
Frequently asked questions
How many cm are in an inch?
Exactly 2.54 cm. Use the Length Converter for feet, meters, miles, and more — all at once.
Do the converters update live?
Yes — enter a value and every other unit updates instantly, so you never have to press a button.
Are the currency rates up to date?
The currency converter pulls daily exchange rates from a public feed, so use it as a reliable reference for travel and quick conversions.