Free Online Unit Converter — Length, Weight, Temperature & More
Converting between units of measurement is a daily need for engineers, students, chefs, travelers, scientists and professionals across every field. Our free unit converter handles 6 categories and 38 different units, all accessible instantly with no installation or account required.
Every conversion uses precise, internationally recognized conversion factors. Results display up to 4 decimal places for maximum accuracy in everyday use.
Supported Unit Categories
📏
Length
Meter, km, mile, foot, inch, yard, cm, mm, nautical mile.
⚖️
Weight & Mass
Kilogram, gram, pound, ounce, milligram, tonne.
🌡️
Temperature
Celsius, Fahrenheit and Kelvin with precise formulas.
🧪
Volume
Liter, mL, gallon (US/UK), cubic meter, cup, tbsp, tsp.
💨
Speed
km/h, m/s, mph and knots for aviation & maritime.
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Area
m², km², hectare, acre, ft², square mile and more.
How to Use the Unit Converter
01
Choose a category
Select from Length, Weight, Temperature, Volume, Speed or Area.
02
Enter your value
Type the number you want to convert. Decimals are fully supported.
03
Select units
Choose the source unit and the target unit from the dropdowns.
04
See the result
Your converted value appears instantly with full precision.
Frequently Asked Questions
How do I convert miles to kilometers?▼
1 mile = 1.609344 km. To convert, multiply the miles value by 1.609344. Our free unit converter does this automatically — just select 'Length', choose Miles → Kilometers and enter your value.
Can this converter handle temperature conversions?▼
Yes. Our unit converter supports Celsius, Fahrenheit and Kelvin. It uses the exact conversion formulas: F = (C × 9/5) + 32, and K = C + 273.15.
What unit categories are supported?▼
The converter supports: Length (9 units), Weight/Mass (6 units), Temperature (3 units), Volume (9 units), Speed (4 units), and Area (7 units) — 38 units in total.
How accurate is the unit converter?▼
Results are calculated with up to 4 decimal places of precision using standard SI conversion factors. For scientific or engineering applications requiring higher precision, we recommend verifying with dedicated specialized tools.
Can I convert liters to US gallons?▼
Yes. 1 US gallon = 3.78541 liters. Select Volume → Liter → US Gallon and enter your value for an instant accurate result.
Frequently Asked Questions