Converters

Unit Converters

Convert between any units instantly. Every converter has dedicated pages for all common conversion pairs - optimised for search and easy to bookmark.

Length

All Units
Length Converter
mm, cm, m, km, inch, foot, yard, mile, nautical mile - all 9 units at once.
9 units simultaneously
 Length
Centimeters to Inches
Convert centimeters to inches with formula and reference table. Reverse conversion included.
cm to in · Formula · Table
 Length
Inches to Centimeters
Convert inches to centimeters with formula and reference table. Reverse conversion included.
in to cm · Formula · Table
 Length
Feet to Meters
Convert feet to meters with formula and reference table. Reverse conversion included.
ft to m · Formula · Table
 Length
Meters to Feet
Convert meters to feet with formula and reference table. Reverse conversion included.
m to ft · Formula · Table
 Length
Kilometers to Miles
Convert kilometers to miles with formula and reference table. Reverse conversion included.
km to mi · Formula · Table
 Length
Miles to Kilometers
Convert miles to kilometers with formula and reference table. Reverse conversion included.
mi to km · Formula · Table
 Length
Millimeters to Inches
Convert millimeters to inches with formula and reference table. Reverse conversion included.
mm to in · Formula · Table
 Length
Yards to Meters
Convert yards to meters with formula and reference table. Reverse conversion included.
yd to m · Formula · Table

Weight

All Units
Weight Converter
kg, g, lb, oz, stone, tonne, mg - all 7 units with one input.
7 units simultaneously
 Weight
Kilograms to Pounds
Convert kilograms to pounds with formula, conversion factor and reference values.
kg to lb · Formula · Table
 Weight
Pounds to Kilograms
Convert pounds to kilograms with formula, conversion factor and reference values.
lb to kg · Formula · Table
 Weight
Grams to Ounces
Convert grams to ounces with formula, conversion factor and reference values.
g to oz · Formula · Table
 Weight
Ounces to Grams
Convert ounces to grams with formula, conversion factor and reference values.
oz to g · Formula · Table
 Weight
Stone to Kilograms
Convert stone to kilograms with formula, conversion factor and reference values.
st to kg · Formula · Table
 Weight
Kilograms to Stone
Convert kilograms to stone with formula, conversion factor and reference values.
kg to st · Formula · Table
 Weight
Tonnes to Kilograms
Convert tonnes to kilograms with formula, conversion factor and reference values.
t to kg · Formula · Table
 Weight
Milligrams to Grams
Convert milligrams to grams with formula, conversion factor and reference values.
mg to g · Formula · Table

Temperature

All Units
Temperature Converter
Celsius, Fahrenheit, Kelvin - all 3 scales with exact formulas.
3 scales · Exact formulas
 Temp
Celsius to Fahrenheit
Convert celsius to fahrenheit with the exact formula, key reference points and a lookup table.
°C to °F · Formula
 Temp
Fahrenheit to Celsius
Convert fahrenheit to celsius with the exact formula, key reference points and a lookup table.
°F to °C · Formula
 Temp
Celsius to Kelvin
Convert celsius to kelvin with the exact formula, key reference points and a lookup table.
°C to K · Formula
 Temp
Kelvin to Celsius
Convert kelvin to celsius with the exact formula, key reference points and a lookup table.
K to °C · Formula
 Temp
Fahrenheit to Kelvin
Convert fahrenheit to kelvin with the exact formula, key reference points and a lookup table.
°F to K · Formula
 Temp
Kelvin to Fahrenheit
Convert kelvin to fahrenheit with the exact formula, key reference points and a lookup table.
K to °F · Formula

Speed

All Units
Speed Converter
km/h, mph, m/s, knots, ft/s - all 5 speed units at once.
5 units
 Speed
Kilometers Per Hour to Miles Per Hour
Convert kilometers per hour to miles per hour with conversion factor and reference table for common speeds.
km/h to mph
 Speed
Miles Per Hour to Kilometers Per Hour
Convert miles per hour to kilometers per hour with conversion factor and reference table for common speeds.
mph to km/h
 Speed
Meters Per Second to Kilometers Per Hour
Convert meters per second to kilometers per hour with conversion factor and reference table for common speeds.
m/s to km/h
 Speed
Knots to Kilometers Per Hour
Convert knots to kilometers per hour with conversion factor and reference table for common speeds.
kn to km/h
 Speed
Knots to Miles Per Hour
Convert knots to miles per hour with conversion factor and reference table for common speeds.
kn to mph
 Speed
Feet Per Second to Meters Per Second
Convert feet per second to meters per second with conversion factor and reference table for common speeds.
ft/s to m/s

Volume

All Units
Volume Converter
Liters, gallons, cups, mL, fl oz, tbsp, tsp - all 9 units at once.
9 units
 Volume
Liters to Gallons
Convert liters to gallons with formula and reference table.
L to gal
 Volume
Gallons to Liters
Convert gallons to liters with formula and reference table.
gal to L
 Volume
Liters to Milliliters
Convert liters to milliliters with formula and reference table.
L to mL
 Volume
Cups to Milliliters
Convert cups to milliliters with formula and reference table.
cup to mL
 Volume
Milliliters to Cups
Convert milliliters to cups with formula and reference table.
mL to cup
 Volume
Tablespoons to Teaspoons
Convert tablespoons to teaspoons with formula and reference table.
tbsp to tsp
 Volume
Liters to Gallons
Convert liters to gallons with formula and reference table.
L to UK gal
 Volume
Fluid Ounces to Milliliters
Convert fluid ounces to milliliters with formula and reference table.
fl oz to mL

Area

All Units
Area Converter
m², ft², km², mi², acres, hectares, yd², in² - 8 area units.
8 units
 Area
Square Meters to Square Feet
Convert square meters to square feet with conversion factor and land area reference.
m² to ft²
 Area
Square Feet to Square Meters
Convert square feet to square meters with conversion factor and land area reference.
ft² to m²
 Area
Acres to Square Meters
Convert acres to square meters with conversion factor and land area reference.
ac to m²
 Area
Hectares to Acres
Convert hectares to acres with conversion factor and land area reference.
ha to ac
 Area
Square Kilometers to Square Miles
Convert square kilometers to square miles with conversion factor and land area reference.
km² to mi²
 Area
Acres to Hectares
Convert acres to hectares with conversion factor and land area reference.
ac to ha

Other Converters

Energy
Energy Converter
Joules, kJ, calories, kcal, kWh, BTU, eV - all energy units.
6 units
 Pressure
Pressure Converter
PSI, bar, pascal, atmosphere, mmHg, kPa pressure unit conversions.
6 units
 Data
Data Storage
Bytes, KB, MB, GB, TB, PB in decimal (SI) and binary (IEC) standards.
Decimal + binary
 Time
Time Converter
Seconds, minutes, hours, days, weeks, months, years - all time units.
7 units
 Cooking
Cooking Converter
Cups, tbsp, tsp, mL with ingredient weight lookup for common foods.
Ingredient weights

Numeral Systems

Numerals
Roman Numerals
Convert numbers to Roman numerals and back. Bidirectional with validation.
Bidirectional
 Numerals
Greek Numerals
Ancient Greek Ionic numeral system converter.
Ionic system
 Numerals
Chinese Numerals
Chinese Hanzi numbers in simplified and formal financial forms.
Simplified + formal
 Numerals
Egyptian Numerals
Ancient Egyptian hieroglyphic number system with symbol explanations.
Hieroglyphics
 Numerals
Mayan Numerals
Mayan vigesimal (base-20) number system with dot-and-bar notation.
Base-20
 Numerals
Babylonian Numerals
Ancient Babylonian cuneiform sexagesimal (base-60) number system.
Base-60