Unit Converter: Convert Length, Weight, Temperature & More

Whether you are following a recipe from another country, checking luggage weight limits for a flight, or converting between imperial and metric for a project, unit conversion is something most people need regularly. Our Unit Converter supports six categories of measurements with instant, accurate results across all common units.

Supported Categories

Length

Convert between metric, imperial, and other length units.

Unit	Abbreviation	Relative to 1 Meter
Millimeter	mm	1,000
Centimeter	cm	100
Meter	m	1
Kilometer	km	0.001
Inch	in	39.3701
Foot	ft	3.28084
Yard	yd	1.09361
Mile	mi	0.000621371

Common conversions to remember:

• 1 inch = 2.54 cm (exact)
• 1 foot = 30.48 cm (exact)
• 1 mile = 1.60934 km
• 1 meter = 3.281 feet

Weight (Mass)

Convert between metric, imperial, and other mass units.

Unit	Abbreviation	Relative to 1 Kilogram
Milligram	mg	1,000,000
Gram	g	1,000
Kilogram	kg	1
Metric Ton	t	0.001
Ounce	oz	35.274
Pound	lb	2.20462

Common conversions to remember:

• 1 pound = 453.592 grams
• 1 kilogram = 2.205 pounds
• 1 ounce = 28.3495 grams

Temperature

Temperature conversions use formulas rather than simple ratios.

Celsius to Fahrenheit:  F = C * 9/5 + 32
Fahrenheit to Celsius:  C = (F - 32) * 5/9
Celsius to Kelvin:      K = C + 273.15

Key reference points:

Event	Celsius	Fahrenheit	Kelvin
Water freezes	0	32	273.15
Room temperature	20-22	68-72	293-295
Body temperature	37	98.6	310.15
Water boils	100	212	373.15

Temperature is the one category where you cannot simply multiply by a conversion factor because the scales have different zero points.

Area

Area conversions use the square of the corresponding length conversion factor.

Unit	Relative to 1 Square Meter
Square Millimeter (mm2)	1,000,000
Square Centimeter (cm2)	10,000
Square Meter (m2)	1
Hectare (ha)	0.0001
Square Kilometer (km2)	0.000001
Square Inch (in2)	1,550.003
Square Foot (ft2)	10.7639
Acre	0.000247105
Square Mile (mi2)	3.861e-7

Common conversions to remember:

• 1 acre = 43,560 square feet = 4,046.86 square meters
• 1 hectare = 10,000 square meters = 2.471 acres
• 1 square mile = 640 acres

Volume

Convert between metric, imperial, and cooking-specific volume units.

Unit	Relative to 1 Liter
Milliliter (mL)	1,000
Liter (L)	1
Cubic Meter (m3)	0.001
Teaspoon (tsp)	202.884
Tablespoon (tbsp)	67.628
Fluid Ounce (fl oz)	33.814
Cup	4.22675
Pint (pt)	2.11338
Quart (qt)	1.05669
Gallon (gal)	0.264172

Note: Volume units listed above are US customary. Imperial (UK) gallons, pints, and fluid ounces are slightly larger than their US counterparts. 1 US gallon = 3.785 liters, while 1 Imperial gallon = 4.546 liters.

Speed

Convert between common speed and velocity units.

Unit	Relative to 1 m/s
Meters per second (m/s)	1
Kilometers per hour (km/h)	3.6
Miles per hour (mph)	2.23694
Feet per second (ft/s)	3.28084
Knots (kn)	1.94384

Common conversions to remember:

• 1 km/h = 0.6214 mph
• 100 km/h = 62.14 mph
• 1 knot = 1.151 mph (used in aviation and maritime)

How to Use Our Unit Converter

1. Select a category (length, weight, temperature, area, volume, or speed)
2. Choose the source unit from the dropdown
3. Enter a value in the input field
4. Choose the target unit from the second dropdown
5. See the result update instantly as you type

Tips

• The converter works in both directions — change either the source or target value and the other updates
• Results show appropriate decimal precision for the unit type
• Temperature conversions handle the offset correctly (not just multiplication)
• Use the tool to double-check manual conversions before submitting important work

Practical Use Cases

Travel

You land in a country that uses metric and see a road sign: 120 km/h speed limit. That is 74.56 mph. The weather forecast says 28 degrees Celsius — a comfortable 82.4 degrees Fahrenheit.

Cooking

A European recipe calls for 200 grams of flour and 150 milliliters of milk. You need roughly 7.05 ounces and 0.634 cups. Precision matters less in cooking, but being in the right ballpark is essential.

Fitness

Your running app reports pace in minutes per kilometer, but you think in miles. A 5:30/km pace equals roughly 8:51/mile. Your weight in the app is in kilograms, but you track progress in pounds.

Real Estate

A property is listed as 1,200 square feet. That is 111.48 square meters. A 2-hectare lot is 4.94 acres. Converting area units helps you compare listings across different markets and countries.

Science and Engineering

Lab measurements often need conversion between SI and CGS units, or between metric and imperial for international collaboration. Getting the conversion factor wrong can derail an entire experiment.

Frequently Asked Questions

Why are there two different gallon sizes? The US gallon (3.785 liters) and the Imperial gallon (4.546 liters) evolved from different historical standards. The US adopted the Queen Anne wine gallon, while the UK later standardized on a larger measure. Always check which system a recipe or specification uses.

Is a metric ton the same as a ton? Not exactly. A metric ton (tonne) is 1,000 kilograms (2,204.6 pounds). A US short ton is 2,000 pounds (907.2 kg). A UK long ton is 2,240 pounds (1,016 kg). The differences are significant at scale.

Why is temperature conversion different from other units? Most unit conversions are proportional — multiply by a constant factor. Temperature scales have different zero points (Fahrenheit’s zero is -17.78 Celsius), so the conversion requires both multiplication and addition.

How precise are the conversions? Our converter uses the internationally accepted conversion factors. For everyday use, the precision is more than sufficient. For scientific applications requiring extreme precision, note that some conversion factors are exact (1 inch = 2.54 cm) while others are rounded approximations.

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Try our free Unit Converter to convert between length, weight, temperature, and more instantly.