Unit Converters

Convert between metric and US units in one step. Every converter shows the exact formula, a quick mental-math shortcut and a conversion chart for the most common values.

Length & distance

Centimeters to InchesConvert centimeters to inches (cm → in). Inches to CentimetersConvert inches to centimeters (in → cm). Centimeters to FeetConvert centimeters to feet (cm → ft). Feet to CentimetersHeight in feet and inches to centimeters. Meters to FeetConvert meters to feet (m → ft). Feet to MetersConvert feet to meters (ft → m). Kilometers to MilesConvert kilometers to miles (km → mi). Miles to KilometersConvert miles to kilometers (mi → km). Millimeters to InchesConvert millimeters to inches (mm → in). Inches to MillimetersConvert inches to millimeters (in → mm). Inches to FeetConvert inches to feet (in → ft). Feet to InchesConvert feet to inches (ft → in). Yards to FeetConvert yards to feet (yd → ft). Feet to YardsConvert feet to yards (ft → yd). Meters to YardsConvert meters to yards (m → yd). Yards to MetersConvert yards to meters (yd → m). Millimeters to CentimetersConvert millimeters to centimeters (mm → cm). Centimeters to MillimetersConvert centimeters to millimeters (cm → mm). Centimeters to MetersConvert centimeters to meters (cm → m). Meters to CentimetersConvert meters to centimeters (m → cm). Miles to FeetConvert miles to feet (mi → ft). Feet to MilesConvert feet to miles (ft → mi). Meters to InchesConvert meters to inches (m → in). Inches to MetersConvert inches to meters (in → m).

Weight & mass

Kilograms to PoundsConvert kilograms to pounds (kg → lb). Pounds to KilogramsConvert pounds to kilograms (lb → kg). Grams to OuncesConvert grams to ounces (g → oz). Ounces to GramsConvert ounces to grams (oz → g). Stones to PoundsConvert stones to pounds (st → lb). Grams to PoundsConvert grams to pounds (g → lb). Pounds to GramsConvert pounds to grams (lb → g). Kilograms to StonesConvert kilograms to stones (kg → st). Stones to KilogramsConvert stones to kilograms (st → kg). Pounds to StonesConvert pounds to stones (lb → st). Ounces to PoundsConvert ounces to pounds (oz → lb). Pounds to OuncesConvert pounds to ounces (lb → oz). Milligrams to GramsConvert milligrams to grams (mg → g). Grams to MilligramsConvert grams to milligrams (g → mg). Kilograms to GramsConvert kilograms to grams (kg → g). Grams to KilogramsConvert grams to kilograms (g → kg).

Temperature

Celsius to FahrenheitConvert degrees Celsius to degrees Fahrenheit (°C → °F). Fahrenheit to CelsiusConvert degrees Fahrenheit to degrees Celsius (°F → °C). Celsius to KelvinConvert degrees Celsius to kelvins (°C → K). Kelvin to CelsiusConvert kelvins to degrees Celsius (K → °C). Fahrenheit to KelvinConvert degrees Fahrenheit to kelvins (°F → K). Kelvin to FahrenheitConvert kelvins to degrees Fahrenheit (K → °F).

Volume & cooking

Liters to GallonsConvert liters to US gallons (L → gal). Gallons to LitersConvert US gallons to liters (gal → L). Milliliters to Fluid OuncesConvert milliliters to US fluid ounces (mL → fl oz). Fluid Ounces to MillilitersConvert US fluid ounces to milliliters (fl oz → mL). Cups to MillilitersConvert US cups to milliliters (cup → mL). Milliliters to CupsConvert milliliters to US cups (mL → cup). Cups to Fluid OuncesConvert US cups to US fluid ounces (cup → fl oz). Milliliters to LitersConvert milliliters to liters (mL → L). Liters to MillilitersConvert liters to milliliters (L → mL). Teaspoons to MillilitersConvert teaspoons to milliliters (tsp → mL). Milliliters to TeaspoonsConvert milliliters to teaspoons (mL → tsp). Tablespoons to MillilitersConvert tablespoons to milliliters (tbsp → mL). Milliliters to TablespoonsConvert milliliters to tablespoons (mL → tbsp). Tablespoons to TeaspoonsConvert tablespoons to teaspoons (tbsp → tsp). Teaspoons to TablespoonsConvert teaspoons to tablespoons (tsp → tbsp). Cups to TablespoonsConvert US cups to tablespoons (cup → tbsp). Tablespoons to CupsConvert tablespoons to US cups (tbsp → cup). Fluid Ounces to CupsConvert US fluid ounces to US cups (fl oz → cup). Cups to LitersConvert US cups to liters (cup → L). Liters to CupsConvert liters to US cups (L → cup). Quarts to LitersConvert US quarts to liters (qt → L). Liters to QuartsConvert liters to US quarts (L → qt). Liters to Fluid OuncesConvert liters to US fluid ounces (L → fl oz). Fluid Ounces to LitersConvert US fluid ounces to liters (fl oz → L). Gallons to Fluid OuncesConvert US gallons to US fluid ounces (gal → fl oz). Quarts to CupsConvert US quarts to US cups (qt → cup). Pints to CupsConvert US pints to US cups (pt → cup). Gallons to CupsConvert US gallons to US cups (gal → cup).

Speed

km/h to mphConvert kilometers per hour to miles per hour (km/h → mph). mph to km/hConvert miles per hour to kilometers per hour (mph → km/h). Knots to mphConvert knots to miles per hour (kn → mph). mph to KnotsConvert miles per hour to knots (mph → kn). Knots to km/hConvert knots to kilometers per hour (kn → km/h). Meters per Second to km/hConvert meters per second to kilometers per hour (m/s → km/h). km/h to Meters per SecondConvert kilometers per hour to meters per second (km/h → m/s).

Area

Square Feet to Square MetersConvert square feet to square meters (ft² → m²). Square Meters to Square FeetConvert square meters to square feet (m² → ft²). Acres to Square FeetConvert acres to square feet (ac → ft²). Hectares to AcresConvert hectares to acres (ha → ac). Square Feet to AcresConvert square feet to acres (ft² → ac). Acres to HectaresConvert acres to hectares (ac → ha). Square Feet to Square YardsConvert square feet to square yards (ft² → yd²). Square Yards to Square FeetConvert square yards to square feet (yd² → ft²).

Data storage

Megabytes to GigabytesConvert megabytes to gigabytes (MB → GB). Gigabytes to MegabytesConvert gigabytes to megabytes (GB → MB). Kilobytes to MegabytesConvert kilobytes to megabytes (KB → MB). Megabytes to KilobytesConvert megabytes to kilobytes (MB → KB). Gigabytes to TerabytesConvert gigabytes to terabytes (GB → TB). Terabytes to GigabytesConvert terabytes to gigabytes (TB → GB).

Pressure

PSI to BarConvert pounds per square inch to bar (psi → bar). Bar to PSIConvert bar to pounds per square inch (bar → psi). Kilopascals to PSIConvert kilopascals to pounds per square inch (kPa → psi). PSI to KilopascalsConvert pounds per square inch to kilopascals (psi → kPa).

Power

Horsepower to KilowattsConvert horsepower to kilowatts (hp → kW). Kilowatts to HorsepowerConvert kilowatts to horsepower (kW → hp). BTU per Hour to WattsConvert BTU per hour to watts (BTU/h → W). Watts to BTU per HourConvert watts to BTU per hour (W → BTU/h).

Energy

Kilojoules to KilocaloriesConvert kilojoules to kilocalories (kJ → kcal). Kilocalories to KilojoulesConvert kilocalories to kilojoules (kcal → kJ). Joules to Calories (small)Convert joules to calories (J → cal). Calories (small) to JoulesConvert calories to joules (cal → J).

Time

Minutes to HoursConvert minutes to hours (min → h). Hours to MinutesConvert hours to minutes (h → min). Seconds to MinutesConvert seconds to minutes (s → min). Hours to DaysConvert hours to days (h → d). Days to WeeksConvert days to weeks (d → wk). Military Time Converter24-hour military time to AM/PM and back.

Numbers

Roman Numeral ConverterNumbers to Roman numerals and back, with steps.

Metric and US units, side by side

The United States uses US customary units — inches, feet, pounds, gallons, degrees Fahrenheit — while most of the world uses the metric system. Since 1959 the two have been tied together by exact definitions: one inch is exactly 2.54 centimeters and one pound is exactly 0.45359237 kilograms. That means every conversion here is exact; results are only rounded for display.

Converting files instead of units?

To change a photo, video or document from one format to another — HEIC to JPG, MOV to MP4, images to PDF — use GlideConvert, our free file converter. It runs in your browser, so files are never uploaded.

Tips for accurate conversions

  • Check which gallon or ounce you mean. US and UK (imperial) gallons and fluid ounces are different sizes, and a fluid ounce (volume) is not the same as an ounce of weight.
  • Round at the end. Convert the full value first, then round the result — rounding early adds up errors.
  • Use the chart for quick lookups. Each converter has a table of the most common values, handy for printing or bookmarking.