Unit Converter: 323 Units Across 43 Categories
Convert between length, mass, pressure, temperature, electrical, and other scientific units. Instant conversion offline on your desktop.
Get the tool mentioned in this guide in the desktop app:Unit Converter
Why a unit converter?
Scientific and engineering work involves many units:
- Metric vs imperial — kilometers, miles, liters, gallons.
- Specialized units — pascals, joules, amperes.
- Easy mistakes — confusing units costs money (Mars probe lost to unit error).
A converter eliminates guessing and ensures accuracy.
Unit categories
Fundamental: - Length (meter, foot, mile, kilometer) - Mass (kilogram, pound, ton, ounce) - Time (second, minute, hour, day) - Temperature (Celsius, Fahrenheit, Kelvin)
Derived: - Area, volume, pressure, energy, power, force, velocity - Electrical (ampere, volt, watt, ohm) - Thermal (specific heat, thermal conductivity) - Polymer and materials science units
Common conversions
- 1 mile = 1.609 km
- 1 pound = 0.454 kg
- 1 gallon = 3.785 liters
- 1 inch = 2.54 cm
- 32°F = 0°C
- 1 kilowatt = 1000 watts
Conversion workflow
1. Select category — length, mass, energy, etc. 2. Enter value — e.g., 5 miles. 3. Select units — from miles, to kilometers. 4. See result — 8.05 km. 5. Copy — grab the result for use.
Frequently asked questions
Is temperature conversion T(K) = T(°C) + 273.15 correct?
Yes, that's the standard formula. Converters handle it automatically.
What about currency or crypto?
This tool focuses on scientific units. Exchange rates change constantly; use a currency converter for that.
Can I convert between unusual units?
323 units across 43 categories covers most scientific needs. Niche units may not be included.