Unit Converter
Convert length, weight, temperature, volume, area, speed, and data units instantly.
This unit converter supports 7 categories with dozens of units. Select a category (length, weight, temperature, volume, area, speed, or digital storage), choose the units to convert between, enter a value, and the result appears instantly. Use the swap button to reverse the conversion direction.
Unit conversion is essential across travel, science, cooking, and engineering. The metric system (SI) is used in most of the world, while the US and partially the UK still use imperial/US customary units. Knowing key conversions — such as miles to kilometres, Fahrenheit to Celsius, or gallons to litres — helps you work seamlessly across both systems.
Frequently Asked Questions
How many meters are in a mile?
One mile equals exactly 1609.344 meters. Conversely, one meter equals approximately 0.000621371 miles. For rough estimates: 1 mile ≈ 1.6 km.
How do you convert Celsius to Fahrenheit?
The formula is °F = °C × 9/5 + 32. For example, 20°C = 68°F. To convert back: °C = (°F − 32) × 5/9. Absolute zero is −273.15°C = −459.67°F = 0 K.
What is the difference between KB and KiB?
KB (Kilobyte) = 1000 bytes in the decimal SI system. KiB (Kibibyte) = 1024 bytes in the binary IEC system. Operating systems often report file sizes in KiB/MiB/GiB but label them as KB/MB/GB, causing confusion. This converter uses the standard definitions: 1 KB = 1000 B, 1 KiB = 1024 B.
How many pounds in a kilogram?
One kilogram equals approximately 2.20462 pounds. One pound equals approximately 0.453592 kg. For a quick estimate, 1 kg ≈ 2.2 lb.
What are knots in speed?
A knot (kn) is one nautical mile per hour, where 1 nautical mile = 1852 m. It is used in aviation and maritime navigation. 1 knot ≈ 1.852 km/h ≈ 1.151 mph.
How do you convert square feet to square meters?
Multiply square feet by 0.092903. For example, 500 sq ft × 0.092903 = 46.45 m². To go the other way, multiply m² by 10.7639. This conversion is common in real estate when comparing US listings to international markets.
How many liters are in a gallon?
In the US system, 1 US gallon = 3.78541 liters. In the UK (Imperial) system, 1 Imperial gallon = 4.54609 liters. To convert US gallons to liters, multiply by 3.785. To convert liters to US gallons, divide by 3.785.
What is the difference between US and Imperial gallons?
A US gallon equals 3.785 liters, while a UK Imperial gallon equals 4.546 liters — about 20% larger. This difference matters for fuel economy: a car rated at 30 mpg (US) gets about 36 mpg (UK). Always check which system is used when comparing fuel consumption.
How do you convert km/h to mph?
Divide km/h by 1.60934. For a quick mental estimate, multiply by 0.6: 100 km/h ≈ 62 mph, 80 km/h ≈ 50 mph. To convert mph to km/h, multiply by 1.60934.
What is the difference between metric and imperial systems?
The metric (SI) system uses base-10 units — metres, kilograms, litres — and is used by most of the world. The imperial/US customary system uses feet, pounds, and gallons, still common in the US and partially in the UK. Science, medicine, and international trade universally use metric; everyday US life uses imperial for distance, weight, and volume.