Convert between metric and imperial units for length, weight, volume and temperature.
Understanding the unit conversion calculation
This unit converter handles the four most-used categories. Choose a category, pick the from and to units, and enter a value to convert instantly — including temperature between Celsius, Fahrenheit and Kelvin.
It covers everyday conversions for cooking, travel, DIY and science.
Try it with these numbers
Take the starting scenario, a category of Length, value of 1. That gives a result of 1,000. Alongside it, Input comes out at 1 km. Change any field and every figure updates as you type.
Using the calculator
- Pick a category (length, weight, volume or temperature).
- Choose the from and to units.
- Enter a value to see the result.
Formula reference
each unit converts through a base unit
temperature uses °C ↔ °F ↔ K formulas
FAQ
What units are supported?
Length (km to inches), weight (tonnes to ounces), volume (m³ to fluid ounces) and temperature (°C, °F, K).
How do I convert Celsius to Fahrenheit?
Multiply by 9/5 and add 32. The converter does this automatically when you pick temperature.
Is it accurate?
Yes — it uses standard conversion factors, so results are precise to several decimals.