⚡Unit Converter

Free Measurement Unit Converter Online for Every Category

This unit converter lets you convert between hundreds of measurement units across eight categories: length, weight, temperature, volume, speed, area, pressure, and energy. Whether you need a quick metric to imperial unit converter for a construction project, a recipe that uses foreign measurements, or a science assignment that requires SI unit conversions, this tool gives you accurate results instantly with a clear conversion factor displayed every time.

All conversions are based on internationally defined standards and are accurate to at least six significant figures, well beyond the precision needed for everyday use.

Length Unit Converter: Inches to Centimeters and More

Length is the most frequently converted measurement type. The metric system uses millimeters, centimeters, meters, and kilometers, while the imperial system uses inches, feet, yards, and miles. The two systems coexist in science, construction, retail, and manufacturing, making a reliable length unit converter essential.

• 1 inch = 2.54 centimeters (exact, by international definition)
• 1 foot = 30.48 centimeters
• 1 yard = 0.9144 meters
• 1 mile = 1.60934 kilometers
• 1 nautical mile = 1.852 kilometers (used in aviation and maritime navigation)

Weight Converter: Pounds to Kilograms and Grams to Ounces

The weight converter covers micrograms through metric tonnes and short/long tons. Key reference values:

• 1 kilogram = 2.20462 pounds
• 1 pound = 453.592 grams
• 1 ounce = 28.3495 grams
• 1 stone = 14 pounds (6.35 kg) — common in UK body weight
• 1 metric tonne = 1,000 kilograms = 2,204.62 pounds

Temperature Converter: Fahrenheit, Celsius, Kelvin, and Rankine

Temperature conversions use direct formulas rather than multiplication factors. Quick reference: water freezes at 0°C / 32°F / 273.15 K, boils at 100°C / 212°F / 373.15 K. Absolute zero is 0 K = −273.15°C = −459.67°F. Rankine is the imperial equivalent of Kelvin, used in some engineering disciplines.

Volume Converter: Liters, Gallons, Fluid Ounces, and More

Volume conversions arise in cooking, chemistry, and fluid engineering. Note that the US gallon (3.785 L) and the UK imperial gallon (4.546 L) are different — this converter includes both. 1 liter = 0.264172 US gallons = 0.219969 imperial gallons.

Speed, Area, Pressure, and Energy

Speed: 1 mph = 1.60934 km/h. 1 knot = 1.852 km/h. Mach 1 ≈ 340.29 m/s at sea level.

Area: 1 acre = 4,046.86 m². 1 hectare = 2.471 acres = 10,000 m².

Pressure: 1 atm = 101,325 Pa = 14.696 psi = 1.01325 bar.

Energy: 1 kWh = 3,600,000 J. 1 kcal = 4,184 J. 1 BTU = 1,055.06 J.